Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	RS INVESTMENT TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2013
Supplement [Text Block]	rsit_SupplementTextBlock	RS INVESTMENT TRUST Supplement to Prospectus (Class A, C, K shares) dated May 1, 2013, and Supplement to Prospectus (Class Y shares) dated May 1, 2013 RS International Growth Fund Effective July 1, 2013, the name of RS International Growth Fund is changed to “RS International Fund” and the Fund’s Prospectuses are changed as follows: The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows: Investments, Risks, and Performance Principal Investment Strategies The Fund normally invests at least 80% of the value of the Fund’s net assets in common stocks and convertible securities issued by (i) companies organized, domiciled, or with a principal office outside of the United States, (ii) companies which primarily trade in a market located outside of the United States, or (iii) companies which do a substantial amount of business outside of the United States, which the investment team considers to be companies that derive at least 50% of their revenue or profits from business outside the United States or have at least 50% of their sales or assets outside the United States. The Fund does not usually focus its investments in a particular industry or country. A significant part of the Fund’s assets will normally be divided among continental Europe, the United Kingdom, Japan, and Asia/Pacific region (including Australia and New Zealand). However, there are no limitations on how much money the Fund can invest in any one country. The Fund may invest up to 20% (measured at the time of purchase) of its total assets in countries in emerging markets when the Fund’s investment team believes it would be appropriate to do so. The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process. The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles. Principal Risks You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows. Equity Securities Risk The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally. Foreign Securities Risk Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Currency Risk Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar. Small Companies Risk Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss. Emerging Market Risk Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. Liquidity Risk Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Cash Position Risk To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited. Overweighting Risk Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark. Underweighting Risk If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark. Portfolio Turnover Risk Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income. RS Global Growth Fund Effective July 1, 2013, the name of RS Global Growth Fund will be changed to “RS Global Fund” and the Fund’s Prospectuses are changed as follows: The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows: Investments, Risks, and Performance Principal Investment Strategies The Fund normally invests at least 80% of the value of its net assets in common stocks, preferred stocks, and other securities convertible into common or preferred stock of publicly traded companies wherever they may be in the world. The Fund may invest in companies of any size anywhere in the world. The Fund expects that substantially all of the securities held by the Fund will be listed on at least one securities exchange. Under normal circumstances, the Fund will invest in companies located in at least three different countries including the United States. The Fund will normally invest 40% or more of its total assets in securities of non-U.S. companies. The Fund may invest any portion of its assets in companies located in emerging markets. The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process. The Fund will not typically seek to hedge its foreign currency exposure (arising from investments denominated in foreign currencies) relative to the U.S. dollar, although the Fund may engage in foreign currency exchange contracts to take advantage of changes in currency exchange rates anticipated by the Fund’s investment team. The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles. Principal Risks You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows. Equity Securities Risk The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally. Foreign Securities Risk Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Currency Risk Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar. Emerging Market Risk Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. Small Companies Risk Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss. Liquidity Risk Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Cash Position Risk To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited. Overweighting Risk Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark. Underweighting Risk If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark. Portfolio Turnover Risk Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.
RS International Growth Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	rsit_SupplementTextBlock	RS INVESTMENT TRUST Supplement to Prospectus (Class A, C, K shares) dated May 1, 2013, and Supplement to Prospectus (Class Y shares) dated May 1, 2013 RS International Growth Fund Effective July 1, 2013, the name of RS International Growth Fund is changed to “RS International Fund” and the Fund’s Prospectuses are changed as follows: The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows: Investments, Risks, and Performance Principal Investment Strategies The Fund normally invests at least 80% of the value of the Fund’s net assets in common stocks and convertible securities issued by (i) companies organized, domiciled, or with a principal office outside of the United States, (ii) companies which primarily trade in a market located outside of the United States, or (iii) companies which do a substantial amount of business outside of the United States, which the investment team considers to be companies that derive at least 50% of their revenue or profits from business outside the United States or have at least 50% of their sales or assets outside the United States. The Fund does not usually focus its investments in a particular industry or country. A significant part of the Fund’s assets will normally be divided among continental Europe, the United Kingdom, Japan, and Asia/Pacific region (including Australia and New Zealand). However, there are no limitations on how much money the Fund can invest in any one country. The Fund may invest up to 20% (measured at the time of purchase) of its total assets in countries in emerging markets when the Fund’s investment team believes it would be appropriate to do so. The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process. The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles. Principal Risks You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows. Equity Securities Risk The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally. Foreign Securities Risk Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Currency Risk Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar. Small Companies Risk Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss. Emerging Market Risk Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. Liquidity Risk Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Cash Position Risk To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited. Overweighting Risk Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark. Underweighting Risk If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark. Portfolio Turnover Risk Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.
RS Global Growth Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement [Text Block]	rsit_SupplementTextBlock	RS INVESTMENT TRUST Supplement to Prospectus (Class A, C, K shares) dated May 1, 2013, and Supplement to Prospectus (Class Y shares) dated May 1, 2013 RS Global Growth Fund Effective July 1, 2013, the name of RS Global Growth Fund will be changed to “RS Global Fund” and the Fund’s Prospectuses are changed as follows: The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows: Investments, Risks, and Performance Principal Investment Strategies The Fund normally invests at least 80% of the value of its net assets in common stocks, preferred stocks, and other securities convertible into common or preferred stock of publicly traded companies wherever they may be in the world. The Fund may invest in companies of any size anywhere in the world. The Fund expects that substantially all of the securities held by the Fund will be listed on at least one securities exchange. Under normal circumstances, the Fund will invest in companies located in at least three different countries including the United States. The Fund will normally invest 40% or more of its total assets in securities of non-U.S. companies. The Fund may invest any portion of its assets in companies located in emerging markets. The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process. The Fund will not typically seek to hedge its foreign currency exposure (arising from investments denominated in foreign currencies) relative to the U.S. dollar, although the Fund may engage in foreign currency exchange contracts to take advantage of changes in currency exchange rates anticipated by the Fund’s investment team. The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles. Principal Risks You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows. Equity Securities Risk The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally. Foreign Securities Risk Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Currency Risk Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar. Emerging Market Risk Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems. Small Companies Risk Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss. Liquidity Risk Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Cash Position Risk To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited. Overweighting Risk Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark. Underweighting Risk If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark. Portfolio Turnover Risk Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.

dei_EntityRegistrantName

RS INVESTMENT TRUST

rsit_SupplementTextBlock

RS INVESTMENT TRUST

Supplement to Prospectus (Class A, C, K shares) dated May 1, 2013, and

Supplement to Prospectus (Class Y shares) dated May 1, 2013

RS International Growth Fund

Effective July 1, 2013, the name of RS International Growth Fund is changed to “RS International Fund” and the Fund’s Prospectuses are changed as follows:

The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows:

Investments, Risks, and Performance

Principal Investment Strategies

The Fund normally invests at least 80% of the value of the Fund’s net assets in common stocks and convertible securities issued by (i) companies organized, domiciled, or with a principal office outside of the United States, (ii) companies which primarily trade in a market located outside of the United States, or (iii) companies which do a substantial amount of business outside of the United States, which the investment team considers to be companies that derive at least 50% of their revenue or profits from business outside the United States or have at least 50% of their sales or assets outside the United States. The Fund does not usually focus its investments in a particular industry or country. A significant part of the Fund’s assets will normally be divided among continental Europe, the United Kingdom, Japan, and Asia/Pacific region (including Australia and New Zealand). However, there are no limitations on how much money the Fund can invest in any one country. The Fund may invest up to 20% (measured at the time of purchase) of its total assets in countries in emerging markets when the Fund’s investment team believes it would be appropriate to do so.

The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process.

The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles.

Principal Risks

You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows.

Equity Securities Risk

The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally.

Foreign Securities Risk

Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund.

Currency Risk

Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar.

Small Companies Risk

Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss.

Emerging Market Risk

Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems.

Liquidity Risk

Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price.

Cash Position Risk

To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited.

Overweighting Risk

Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark.

Underweighting Risk

If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark.

Portfolio Turnover Risk

Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.

RS Global Growth Fund

Effective July 1, 2013, the name of RS Global Growth Fund will be changed to “RS Global Fund” and the Fund’s Prospectuses are changed as follows:

The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows:

Investments, Risks, and Performance

Principal Investment Strategies

The Fund normally invests at least 80% of the value of its net assets in common stocks, preferred stocks, and other securities convertible into common or preferred stock of publicly traded companies wherever they may be in the world. The Fund may invest in companies of any size anywhere in the world. The Fund expects that substantially all of the securities held by the Fund will be listed on at least one securities exchange.

Under normal circumstances, the Fund will invest in companies located in at least three different countries including the United States. The Fund will normally invest 40% or more of its total assets in securities of non-U.S. companies. The Fund may invest any portion of its assets in companies located in emerging markets.

The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process.

The Fund will not typically seek to hedge its foreign currency exposure (arising from investments denominated in foreign currencies) relative to the U.S. dollar, although the Fund may engage in foreign currency exchange contracts to take advantage of changes in currency exchange rates anticipated by the Fund’s investment team.

The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles.

Principal Risks

You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows.

Equity Securities Risk

The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally.

Foreign Securities Risk

Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund.

Currency Risk

Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar.

Emerging Market Risk

Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems.

Small Companies Risk

Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss.

Liquidity Risk

Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price.

Cash Position Risk

To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited.

Overweighting Risk

Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark.

Underweighting Risk

If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark.

Portfolio Turnover Risk

Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.

Risk/Return:

rr_RiskReturnAbstract

Supplement [Text Block]

rsit_SupplementTextBlock

RS INVESTMENT TRUST

Supplement to Prospectus (Class A, C, K shares) dated May 1, 2013, and

Supplement to Prospectus (Class Y shares) dated May 1, 2013

RS Global Growth Fund

Effective July 1, 2013, the name of RS Global Growth Fund will be changed to “RS Global Fund” and the Fund’s Prospectuses are changed as follows:

The sub-sections titled “Principal Investment Strategies” and “Principal Risks” under the section titled “Investments, Risks, and Performance,” and the section titled “Management of the Fund” are amended and restated in their entirety as follows:

Investments, Risks, and Performance

Principal Investment Strategies

The Fund normally invests at least 80% of the value of its net assets in common stocks, preferred stocks, and other securities convertible into common or preferred stock of publicly traded companies wherever they may be in the world. The Fund may invest in companies of any size anywhere in the world. The Fund expects that substantially all of the securities held by the Fund will be listed on at least one securities exchange.

Under normal circumstances, the Fund will invest in companies located in at least three different countries including the United States. The Fund will normally invest 40% or more of its total assets in securities of non-U.S. companies. The Fund may invest any portion of its assets in companies located in emerging markets.

The Fund’s investment team employs both fundamental analysis and quantitative screening in seeking to identify companies across the market capitalization spectrum that it believes can sustain long-term growth. Valuation is also an integral part of the investment process. The investment team seeks to identify companies that it believes possess strong earnings quality, operational efficiency, sound management, favorable growth characteristics, attractive valuations, and that enjoy favorable market sentiment. The Fund’s investment team monitors macroeconomic and political trends, as well as risk exposures, as part of the overall investment process.

The Fund will not typically seek to hedge its foreign currency exposure (arising from investments denominated in foreign currencies) relative to the U.S. dollar, although the Fund may engage in foreign currency exchange contracts to take advantage of changes in currency exchange rates anticipated by the Fund’s investment team.

The Fund also may invest in foreign issuers through American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), Global Depositary Receipts (GDRs), or similar investment vehicles.

Principal Risks

You may lose money by investing in the Fund. The Fund may not achieve its investment objective. The principal risks of investing in the Fund, which could adversely affect its net asset value and total return, are as follows.

Equity Securities Risk

The value of a company’s stock may decline in response to factors affecting that particular company or stock markets generally.

Foreign Securities Risk

Foreign securities are subject to political, regulatory, and economic risks not present in domestic investments. In addition, when the Fund buys securities denominated in a foreign currency, there are special risks such as changes in currency exchange rates and the risk that a foreign government could regulate foreign exchange transactions. In addition, to the extent that investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund.

Currency Risk

Investments in foreign securities are often denominated and traded in foreign currencies. The value of the Fund’s assets may be affected favorably or unfavorably by currency exchange rates, currency exchange control regulations, and restrictions or prohibitions on the repatriation of foreign currencies. To attempt to protect against changes in currency exchange rates, the Fund may, but will not necessarily, engage in forward foreign-currency exchange transactions. The use of foreign exchange transactions to reduce foreign-currency exposure can eliminate some or all of the benefit of an increase in the value of a foreign currency versus the U.S. dollar.

Emerging Market Risk

Risks of investing in emerging markets include greater political and economic instability, greater volatility in currency exchange rates, less developed securities markets, possible trade barriers, currency transfer restrictions, a more limited number of potential buyers, an emerging market country’s dependence on revenue from particular commodities or international aid, less governmental supervision and regulation, unavailability of currency hedging techniques, differences in auditing and financial reporting standards, and less developed legal systems.

Small Companies Risk

Small companies may be subject to a number of risks not associated with larger, more established companies, potentially making their stock prices more volatile and increasing the risk of loss.

Liquidity Risk

Lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by RS Investments, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price.

Cash Position Risk

To the extent that the Fund holds assets in cash and cash equivalents and not in the investments previously described, the ability of the Fund to meet its objective may be limited.

Overweighting Risk

Overweighting investments in an industry or group of industries relative to the Fund’s benchmark increases the risk that the Fund will underperform its benchmark because a general decline in the prices of stocks in that industry or group of industries will affect the Fund to a greater extent than its benchmark.

Underweighting Risk

If the Fund underweights its investment in an industry or group of industries relative to the Fund’s benchmark, the Fund will participate in any general increase in the value of companies in that industry or group of industries to a lesser extent than the Fund’s benchmark.

Portfolio Turnover Risk

Frequent purchases and sales of portfolio securities may result in higher Fund expenses and may result in more significant distributions of short-term capital gains to investors, which are taxed as ordinary income.