497

400 Howard Street P.O.Box 7101 San Francisco, CA 94105 Tel +1 415 670 7987 Fax +1 415 618 5462 Edward.Baer@blackrock.com

April 15, 2014

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

RE: iShares Trust (the “Registrant”)

Securities Act File No. 333-92935

Investment Company Act File No. 811-09729

Ladies and Gentlemen:

On behalf of the Registrant and pursuant to Rule 497 under the Securities Act of 1933, as amended, attached for filing are exhibits containing interactive data format risk/return summary information that mirrors the risk/return summary information in the 497 filing, dated April 2, 2014 to the prospectus for iShares Nasdaq Biotechnology ETF. The purpose of this filing is to submit the 497 dated April 2, 2014 in XBRL.

If you have any questions regarding this filing, please contact Benjamin Haskin of Willkie Farr & Gallagher LLP at (202) 303-1124 or me at (415) 670-7987.

Very truly yours,

/s/ Edward Baer

Edward Baer

cc: Benjamin Haskin, Esq.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Aug. 01, 2013
Document Creation Date	dei_DocumentCreationDate	Apr. 03, 2014

XML

iShares Nasdaq Biotechnology ETF

iSHARES® NASDAQ BIOTECHNOLOGY ETF
Ticker: IBB                                 Stock Exchange: NASDAQ

Investment Objective

The iShares Nasdaq Biotechnology ETF (the “Fund”) seeks to track the investment results of an index composed of biotechnology and pharmaceutical equities listed on the NASDAQ.

Fees and Expenses

The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except interest expenses, taxes, brokerage expenses, future distribution fees or expenses, and extraordinary expenses.

You may also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the Example that follows:

Annual Fund Operating Expenses
(ongoing expenses that you pay each year as a
percentage of the value of your investments)

Annual Fund Operating Expenses	Management Fees	Distribution and Service (12b-1) Fees	Other Expenses	Total Annual Fund Operating Expenses
iShares Nasdaq Biotechnology ETF	0.48%	none	none	0.48%

Example.

This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
iShares Nasdaq Biotechnology ETF	49	154	269	604

Portfolio Turnover.

The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 14% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to track the investment results of the NASDAQ Biotechnology Index (the “Underlying Index”), which contains securities of NASDAQ^® listed companies that are classified according to the Industry Classification Benchmark as either biotechnology or pharmaceuticals and that also meet other eligibility criteria determined by The NASDAQ OMX Group, Inc. (“NASDAQ OMX”), including minimum market capitalization and liquidity requirements. The Underlying Index may include large-, mid- or small-capitalization companies, and components primarily include biotechnology, healthcare and pharmaceuticals companies. The components of the Underlying Index may change over time.

BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued.

Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies.

BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index.

The Fund generally invests at least 90% of its assets in securities of the Underlying Index and in depositary receipts representing securities of the Underlying Index. The Fund may invest the remainder of its assets in certain futures, options and swap contracts, cash and cash equivalents, including money market funds advised by BFA or its affiliates, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund.

The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of the collateral received).

The Underlying Index is sponsored by an organization (the “Index Provider”) that is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. The Fund’s Index Provider is NASDAQ OMX.

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.

Summary of Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to the principal risks noted below, any of which may adversely affect the Fund's net asset value per share ("NAV"), trading price, yield, total return and ability to meet its investment objective.

Asset Class Risk. Securities in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general securities markets or other asset classes.

Biotechnology Industry Risk. Biotechnology companies face intense competition and the potential for rapid product obsolescence. Biotechnology companies may be adversely affected by the loss or impairment of intellectual property rights or changes in government regulations.

Concentration Risk. To the extent that the Fund's investments are concentrated in a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class, the Fund may be susceptible to loss due to adverse occurrences affecting that issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class.

Equity Securities Risk. Equity securities are subject to changes in value and their values may be more volatile than those of other asset classes.

Healthcare Sector Risk. The healthcare sector may be affected by government regulations and government healthcare programs, increases or decreases in the cost of medical products and services and product liability claims, among other factors. Many healthcare companies are heavily dependent on patent protection, and the expiration of a patent may adversely affect their profitability. Healthcare companies are subject to competitive forces that may result in price discounting, and may be thinly capitalized and susceptible to product obsolescence.

Index-Related Risk. There is no guarantee that the Fund will achieve a high degree of correlation to the Underlying Index and therefore achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund's ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data may occur from time to time and may not be identified and corrected for a period of time, and may have an adverse impact on the Fund and its Shareholders.

Issuer Risk. Fund performance depends on the performance of individual securities to which the Fund has exposure. Changes in the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline.

Management Risk. As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BFA's investment management strategy may not produce the intended results.

Market Risk. The Fund could lose money over short periods due to short-term market movements and over longer periods during market downturns.

Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.

Passive Investment Risk. The Fund is not actively managed and BFA does not attempt to take defensive positions under any market conditions, including declining markets.

Pharmaceuticals Industry Risk. Companies in the pharmaceuticals industry may be affected by industry competition, dependencies on a limited number of products, obsolescence of products, government approvals and regulations, loss or impairment of intellectual property rights and litigation regarding product liability.

Risk of Investing in the United States. The United States is a significant country in which the Fund invests. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

Securities Lending Risk. The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the Fund's loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of the collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund.

Tracking Error Risk. Tracking error is the divergence of the Fund's performance from that of the Underlying Index. Tracking error may occur because of differences between the securities held in the Fund's portfolio and those included in the Underlying Index, pricing differences, transaction costs, the Fund's holding of cash, differences in timing of the accrual of dividends, changes to the Underlying Index or the need to meet various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not.

Performance Information

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund. Both assume that all dividends and distributions have been reinvested in the Fund. Two versions of the Underlying Index are calculated by the Index Provider - - the price return index, which is calculated without regard to cash dividends, and the total return index, which is calculated by reinvesting cash dividends. As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return) because it reflects the Fund’s inclusion of dividends. Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return). The performance of both the NASDAQ Biotechnology Index (total return) and the NASDAQ Biotechnology Index (price return) are shown in the Average Annual Total Returns table, below. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Supplemental information about the Fund’s performance is shown under the heading Total Return Information in the Supplemental Information section of the Fund's prospectus (the “Prospectus”).

Year-by-Year Returns (Years Ended December 31)

The best calendar quarter return during the periods shown above was 31.16% in the 2nd quarter of 2003; the worst was -15.30% in the 1st quarter of 2005.

Updated performance information is available at www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).

Average Annual Total Returns
(for the periods ended December 31, 2012)

Average Annual Total Returns		One Year	Five Years	Ten Years	Inception Date
iShares Nasdaq Biotechnology ETF		31.96%	11.34%	10.86%	Feb. 05, 2001
iShares Nasdaq Biotechnology ETF Return After Taxes on Distributions	[1]	31.86%	11.29%	10.83%
iShares Nasdaq Biotechnology ETF Return After Taxes on Distributions and Sale of Fund Shares	[1]	20.90%	9.90%	9.73%
iShares Nasdaq Biotechnology ETF NASDAQ Biotechnology Index (total return) (Index returns do not reflect deductions for fees, expenses, or taxes)	[2]	32.29%	11.60%
iShares Nasdaq Biotechnology ETF NASDAQ Biotechnology Index (price return) (Index returns do not reflect deductions for fees, expenses, or taxes)	[2]	31.91%	11.37%	11.16%

[1] The Fund's total return for the six months ended June 30, 2013 was 26.70%.

[1] After-tax returns in the table above are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state or local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to tax-exempt investors or investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts ("IRAs"). Fund returns after taxes on distributions and sales of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, Fund returns after taxes on distributions and sales of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.

[2] As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return). Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return).

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Prospectus Date	rr_ProspectusDate	Aug. 01, 2013
iShares Nasdaq Biotechnology ETF
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	iSHARES® NASDAQ BIOTECHNOLOGY ETF Ticker: IBB                                 Stock Exchange: NASDAQ
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The iShares Nasdaq Biotechnology ETF (the “Fund”) seeks to track the investment results of an index composed of biotechnology and pharmaceutical equities listed on the NASDAQ.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you will incur if you own shares of the Fund. The investment advisory agreement between iShares Trust (the “Trust”) and BlackRock Fund Advisors (“BFA”) (the “Investment Advisory Agreement”) provides that BFA will pay all operating expenses of the Fund, except interest expenses, taxes, brokerage expenses, future distribution fees or expenses, and extraordinary expenses. You may also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investments)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover.
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 14% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	14.00%
Expense Exchange Traded Fund Commissions [Text]	rr_ExpenseExchangeTradedFundCommissions	You may also incur usual and customary brokerage commissions when buying or selling shares of the Fund, which are not reflected in the Example that follows:
Expense Example [Heading]	rr_ExpenseExampleHeading	Example.
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of owning shares of the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to track the investment results of the NASDAQ Biotechnology Index (the “Underlying Index”), which contains securities of NASDAQ® listed companies that are classified according to the Industry Classification Benchmark as either biotechnology or pharmaceuticals and that also meet other eligibility criteria determined by The NASDAQ OMX Group, Inc. (“NASDAQ OMX”), including minimum market capitalization and liquidity requirements. The Underlying Index may include large-, mid- or small-capitalization companies, and components primarily include biotechnology, healthcare and pharmaceuticals companies. The components of the Underlying Index may change over time. BFA uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the Fund will substantially outperform the Underlying Index but also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies. BFA uses a representative sampling indexing strategy to manage the Fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return variability and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities in the Underlying Index. The Fund generally invests at least 90% of its assets in securities of the Underlying Index and in depositary receipts representing securities of the Underlying Index. The Fund may invest the remainder of its assets in certain futures, options and swap contracts, cash and cash equivalents, including money market funds advised by BFA or its affiliates, as well as in securities not included in the Underlying Index, but which BFA believes will help the Fund track the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. The Fund may lend securities representing up to one-third of the value of the Fund's total assets (including the value of the collateral received). The Underlying Index is sponsored by an organization (the “Index Provider”) that is independent of the Fund and BFA. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index. The Fund’s Index Provider is NASDAQ OMX. Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.
Risk [Heading]	rr_RiskHeading	Summary of Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to the principal risks noted below, any of which may adversely affect the Fund's net asset value per share ("NAV"), trading price, yield, total return and ability to meet its investment objective. Asset Class Risk. Securities in the Underlying Index or in the Fund's portfolio may underperform in comparison to the general securities markets or other asset classes. Biotechnology Industry Risk. Biotechnology companies face intense competition and the potential for rapid product obsolescence. Biotechnology companies may be adversely affected by the loss or impairment of intellectual property rights or changes in government regulations. Concentration Risk. To the extent that the Fund's investments are concentrated in a particular issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class, the Fund may be susceptible to loss due to adverse occurrences affecting that issuer or issuers, country, group of countries, region, market, industry, group of industries, sector or asset class. Equity Securities Risk. Equity securities are subject to changes in value and their values may be more volatile than those of other asset classes. Healthcare Sector Risk. The healthcare sector may be affected by government regulations and government healthcare programs, increases or decreases in the cost of medical products and services and product liability claims, among other factors. Many healthcare companies are heavily dependent on patent protection, and the expiration of a patent may adversely affect their profitability. Healthcare companies are subject to competitive forces that may result in price discounting, and may be thinly capitalized and susceptible to product obsolescence. Index-Related Risk. There is no guarantee that the Fund will achieve a high degree of correlation to the Underlying Index and therefore achieve its investment objective. Market disruptions and regulatory restrictions could have an adverse effect on the Fund's ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data may occur from time to time and may not be identified and corrected for a period of time, and may have an adverse impact on the Fund and its Shareholders. Issuer Risk. Fund performance depends on the performance of individual securities to which the Fund has exposure. Changes in the financial condition or credit rating of an issuer of those securities may cause the value of the securities to decline. Management Risk. As the Fund may not fully replicate the Underlying Index, it is subject to the risk that BFA's investment management strategy may not produce the intended results. Market Risk. The Fund could lose money over short periods due to short-term market movements and over longer periods during market downturns. Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS, AMONG OTHERS, MAY LEAD TO THE FUND'S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV. Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers. Passive Investment Risk. The Fund is not actively managed and BFA does not attempt to take defensive positions under any market conditions, including declining markets. Pharmaceuticals Industry Risk. Companies in the pharmaceuticals industry may be affected by industry competition, dependencies on a limited number of products, obsolescence of products, government approvals and regulations, loss or impairment of intellectual property rights and litigation regarding product liability. Risk of Investing in the United States. The United States is a significant country in which the Fund invests. Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure. Securities Lending Risk. The Fund may engage in securities lending. Securities lending involves the risk that the Fund may lose money because the borrower of the Fund's loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of the collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. These events could also trigger adverse tax consequences for the Fund. Tracking Error Risk. Tracking error is the divergence of the Fund's performance from that of the Underlying Index. Tracking error may occur because of differences between the securities held in the Fund's portfolio and those included in the Underlying Index, pricing differences, transaction costs, the Fund's holding of cash, differences in timing of the accrual of dividends, changes to the Underlying Index or the need to meet various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. Tracking error also may result because the Fund incurs fees and expenses, while the Underlying Index does not.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk. The Fund may invest a large percentage of its assets in securities issued by or representing a small number of issuers. As a result, the Fund's performance may depend on the performance of a small number of issuers.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund. Both assume that all dividends and distributions have been reinvested in the Fund. Two versions of the Underlying Index are calculated by the Index Provider - - the price return index, which is calculated without regard to cash dividends, and the total return index, which is calculated by reinvesting cash dividends. As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return) because it reflects the Fund’s inclusion of dividends. Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return). The performance of both the NASDAQ Biotechnology Index (total return) and the NASDAQ Biotechnology Index (price return) are shown in the Average Annual Total Returns table, below. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Supplemental information about the Fund’s performance is shown under the heading Total Return Information in the Supplemental Information section of the Fund's prospectus (the “Prospectus”).
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund.
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	Two versions of the Underlying Index are calculated by the Index Provider - - the price return index, which is calculated without regard to cash dividends, and the total return index, which is calculated by reinvesting cash dividends. As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return) because it reflects the Fund’s inclusion of dividends. Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return).
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-iShares (1-800-474-2737) (toll free)
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.iShares.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Year-by-Year Returns (Years Ended December 31)
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	The best calendar quarter return during the periods shown above was 31.16% in the 2nd quarter of 2003; the worst was -15.30% in the 1st quarter of 2005. Updated performance information is available at www.iShares.com or by calling 1-800-iShares (1-800-474-2737) (toll free).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2012)
Performance Table Market Index Changed	rr_PerformanceTableMarketIndexChanged	As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return) because it reflects the Fund’s inclusion of dividends. Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return).
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns in the table above are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state or local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and after-tax returns shown are not relevant to tax-exempt investors or investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts (“IRAs”).
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Fund returns after taxes on distributions and sales of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, Fund returns after taxes on distributions and sales of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.
iShares Nasdaq Biotechnology ETF | iShares Nasdaq Biotechnology ETF
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.48%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.48%
1 Year	rr_ExpenseExampleYear01	$ 49
3 Years	rr_ExpenseExampleYear03	154
5 Years	rr_ExpenseExampleYear05	269
10 Years	rr_ExpenseExampleYear10	$ 604
2003	rr_AnnualReturn2003	45.59%
2004	rr_AnnualReturn2004	4.38%
2005	rr_AnnualReturn2005	2.74%
2006	rr_AnnualReturn2006	0.57%
2007	rr_AnnualReturn2007	4.37%
2008	rr_AnnualReturn2008	(12.68%)
2009	rr_AnnualReturn2009	15.48%
2010	rr_AnnualReturn2010	14.93%
2011	rr_AnnualReturn2011	11.86%
2012	rr_AnnualReturn2012	31.96%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	The Fund's total return for the six months ended
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2013
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	26.70%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	best
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2003
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	31.16%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	worst
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2005
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(15.30%)
One Year	rr_AverageAnnualReturnYear01	31.96%
Five Years	rr_AverageAnnualReturnYear05	11.34%
Ten Years	rr_AverageAnnualReturnYear10	10.86%
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 05, 2001
iShares Nasdaq Biotechnology ETF | Return After Taxes on Distributions | iShares Nasdaq Biotechnology ETF
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	31.86%	[2]
Five Years	rr_AverageAnnualReturnYear05	11.29%	[2]
Ten Years	rr_AverageAnnualReturnYear10	10.83%	[2]
iShares Nasdaq Biotechnology ETF | Return After Taxes on Distributions and Sale of Fund Shares | iShares Nasdaq Biotechnology ETF
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	20.90%	[2]
Five Years	rr_AverageAnnualReturnYear05	9.90%	[2]
Ten Years	rr_AverageAnnualReturnYear10	9.73%	[2]
iShares Nasdaq Biotechnology ETF | NASDAQ Biotechnology Index (total return) (Index returns do not reflect deductions for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	32.29%	[3]
Five Years	rr_AverageAnnualReturnYear05	11.60%	[3]
Ten Years	rr_AverageAnnualReturnYear10		[3]
iShares Nasdaq Biotechnology ETF | NASDAQ Biotechnology Index (price return) (Index returns do not reflect deductions for fees, expenses, or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	31.91%	[3]
Five Years	rr_AverageAnnualReturnYear05	11.37%	[3]
Ten Years	rr_AverageAnnualReturnYear10	11.16%	[3]

[1] The Fund's total return for the six months ended June 30, 2013 was 26.70%.

[2] After-tax returns in the table above are calculated using the historical highest individual U.S. federal marginal income tax rates and do not reflect the impact of state or local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to tax-exempt investors or investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts ("IRAs"). Fund returns after taxes on distributions and sales of Fund shares are calculated assuming that an investor has sufficient capital gains of the same character from other investments to offset any capital losses from the sale of Fund shares. As a result, Fund returns after taxes on distributions and sales of Fund shares may exceed Fund returns before taxes and/or returns after taxes on distributions.

[3] As of April 3, 2014, the Fund compares its performance to the NASDAQ Biotechnology Index (total return). Previously, the Fund compared its performance to the NASDAQ Biotechnology Index (price return).

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	Other
Document Period End Date	dei_DocumentPeriodEndDate	Mar. 31, 2013
Registrant Name	dei_EntityRegistrantName	iSHARES TRUST
Central Index Key	dei_EntityCentralIndexKey	0001100663
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Apr. 03, 2014
Document Effective Date	dei_DocumentEffectiveDate	Apr. 03, 2014
Prospectus Date	rr_ProspectusDate	Aug. 01, 2013