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ING MUTUAL FUNDS

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ING Mutual Funds

ING International Small Cap Fund

(“Fund”)

Supplement dated March 15, 2013

to the Fund’s Class A, Class B, Class C, Class I, Class O, and Class W

Prospectus dated February 28, 2013; and

to the Fund’s Class A, Class B, Class C, Class I, Class O and Class W

Summary Prospectus dated February 28, 2013

(each a “Prospectus” and collectively “Prospectuses”)

On March 7, 2013, the Fund’s Board of Trustees (“Board”) approved replacing Schroder Investment Management North America Inc. (“Schroders”) as a sub-adviser to the Fund with Wellington Management Company, LLP (“Wellington Management”) effective beginning April 30, 2013. Schroders currently manages a portion of the Fund’s assets, and Acadian Asset Management LLC (“Acadian”) currently manages the other portion of the Fund’s assets. From the close of business on April 14, 2013 through the close of business on April 29, 2013, the Fund will be in a “transition period” during which time a transition manager will sell all or most of the assets managed by Schroders and the transition manager may hold a large portion of the Fund’s assets in temporary investments. During this time, the Fund may not be pursuing its investment objective and strategies, and limitation on permissible investments and investment restrictions will not apply. The sales and purchases of securities during the transition period are expected to result in significant buy and sell transactions. Such transactions may be made at a disadvantageous time and may result in the realization of taxable gains or losses for the Fund resulting in taxable distributions to the Fund’s shareholders. In addition, these transactions will also result in transactional costs, which are ultimately borne by shareholders. Effective on or about April 30, 2013, Acadian and Wellington Management will be the two sub-advisers managing the Fund’s assets. In conjunction with the change to one of the Fund’s sub-advisers from Schroders to Wellington Management, Matthew Dobbs will be replaced as portfolio manager for the portion of the Fund’s assets managed by Schroders. Simon H. Thomas and Daniel Maguire will be added as portfolio managers for the portion of the Fund’s assets allocated to Wellington Management.

Effective on the close of business April 14, 2013, the Fund’s Prospectuses are hereby revised as follows:

1.	The subsection entitled “Fees and Expenses of the Fund – Portfolio Turnover” of the Fund’s Prospectuses is hereby deleted and replaced with the following:

Portfolio Turnover % of average value of portfolio

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transactions costs and may mean higher taxes if you are investing in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Expense Examples, affect the Fund’s performance.

During the most recent fiscal year, the Fund’s portfolio turnover rate was 31% of the average value of its portfolio.

At the close of business on April 14, 2013, Schroder Investment Management North America Inc. (“Schroders”) will be terminated as a sub-adviser to the Fund. On or about April 30, 2013, Acadian Asset Management LLC and Wellington Management Company, LLP (“Wellington Management”) will be the two sub-advisers managing the Fund’s assets. During the period from the close of business April 14, 2013 through the close of business on April 29, 2013, the Fund is in a transition period during which time a transition manager will sell all or most of the assets managed by Schroders in preparation for Wellington Management managing these assets beginning on or about April 30, 2013, which will result in significant buy and sell transactions. These transactions could result in the realization of taxable gains or losses for the Fund resulting in taxable distributions to the Fund’s shareholders. In addition, these transactions will result in transaction costs which will be borne by the shareholders.

2.	The section entitled “Principal Investment Strategies” of the Fund’s Prospectuses is hereby deleted and replaced with the following:

PRINCIPAL INVESTMENT STRATEGIES

Under normal market conditions, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in securities of small market capitalization companies. The Fund will provide shareholders with at least 60 days’ prior notice of any change in this investment policy. The Fund currently considers small-capitalization companies to be those that have a market capitalization, at the time of purchase, of up to $5 billion. At least 65% of the Fund’s assets will normally be invested in companies located outside the United States, including companies located in countries with emerging securities markets. The Fund may invest up to 35% of its assets in U.S. issuers. The Fund may hold both growth and value stocks and at times may favor one over the other based on available opportunities.

The Fund invests primarily in common stocks or securities convertible into common stocks of international issuers, but may invest from time to time in such instruments as forward currency contracts, futures contracts, rights, and depositary receipts. The Fund may invest in forward currency contracts or futures contracts to hedge currency and for implementation of a currency model within the portfolio. The Fund may invest in futures contracts to allow market exposure in a cost efficient way, maintain exposure to an asset class in the case of large cash flows, and to have access to a particular market in which the Fund wishes to invest.

The Fund may invest in other investment companies, including exchange-traded funds, to the extent permitted under the Investment Company Act of 1940, as amended, and the rules, regulations, and exemptive orders thereunder (“1940 Act”).

Acadian Asset Management LLC (“Acadian”) and Wellington Management Company, LLP (“Wellington Management”) (each a “Sub-Adviser” and collectively “Sub-Advisers”) provide the day-to-day management of the Fund. The Sub-Advisers act independently of each other and use their own methodology for selecting investments. ING Investments, LLC, the Fund’s investment adviser, will determine the amount of Fund assets allocated to Acadian and Wellington Management.

Each Sub-Adviser may sell securities for a variety of reasons, such as to secure gains, limit losses, or redeploy assets into opportunities believed to be more promising, among others.

The Fund may lend portfolio securities on a short-term or long-term basis, up to 30% of its total assets.

Acadian Asset Management LLC

Acadian employs a quantitative investment process which is driven by proprietary valuation models that combine a bottom-up view of the attractiveness of individual securities within each market with a top-down view of the attractiveness of each region/industry group, thereby capturing value-added at both the stock and the region/industry levels.

Wellington Management Company, LLP

Wellington Management uses its proprietary global research capabilities to identify stocks for the portfolio. Wellington Management takes a local-regional approach to research and stock selection using a number of different sources to identify purchase candidates, including the firm’s proprietary research, local brokers, and company and local referrals. The sources used depend greatly on the issuer’s region and industry. Long-term investment themes based on general economic factors, along with cost of capital and liquidity forecasts, are important in targeting research efforts.

A candidate for purchase in the portfolio is subjected to extensive fundamental analysis. Wellington Management seeks candidates that exhibit some combination of:

•

a well-articulated business plan,

•

experienced management,

•

a sustainable competitive advantage, and

•

strong financial characteristics.

In addition, valuation analysis, including relevant industry valuations, is used to compare the results to a global and local peer group of companies. Companies that compare favorably with the fundamentals, growth, and valuation characteristics of peers are strong candidates for the portfolio. In implementing purchase decisions, consideration is given to size, liquidity and volatility. Sell decisions are based on changing fundamentals or valuations, or on finding better opportunities for the portfolio. Industry weights are likely to favor sectors in which smaller companies have long-term competitive advantages or are expected to benefit from extended growth opportunities.

Risk/Return:

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Portfolio Turnover [Heading]

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Portfolio Turnover % of average value of portfolio

Portfolio Turnover, Rate

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31.00%

Strategy Narrative [Text Block]

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Under normal market conditions, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes) in securities of small market capitalization companies. The Fund will provide shareholders with at least 60 days’ prior notice of any change in this investment policy. The Fund currently considers small-capitalization companies to be those that have a market capitalization, at the time of purchase, of up to $5 billion. At least 65% of the Fund’s assets will normally be invested in companies located outside the United States, including companies located in countries with emerging securities markets. The Fund may invest up to 35% of its assets in U.S. issuers. The Fund may hold both growth and value stocks and at times may favor one over the other based on available opportunities.

The Fund invests primarily in common stocks or securities convertible into common stocks of international issuers, but may invest from time to time in such instruments as forward currency contracts, futures contracts, rights, and depositary receipts. The Fund may invest in forward currency contracts or futures contracts to hedge currency and for implementation of a currency model within the portfolio. The Fund may invest in futures contracts to allow market exposure in a cost efficient way, maintain exposure to an asset class in the case of large cash flows, and to have access to a particular market in which the Fund wishes to invest.

The Fund may invest in other investment companies, including exchange-traded funds, to the extent permitted under the Investment Company Act of 1940, as amended, and the rules, regulations, and exemptive orders thereunder (“1940 Act”).

Acadian Asset Management LLC (“Acadian”) and Wellington Management Company, LLP (“Wellington Management”) (each a “Sub-Adviser” and collectively “Sub-Advisers”) provide the day-to-day management of the Fund. The Sub-Advisers act independently of each other and use their own methodology for selecting investments. ING Investments, LLC, the Fund’s investment adviser, will determine the amount of Fund assets allocated to Acadian and Wellington Management.

Each Sub-Adviser may sell securities for a variety of reasons, such as to secure gains, limit losses, or redeploy assets into opportunities believed to be more promising, among others.

The Fund may lend portfolio securities on a short-term or long-term basis, up to 30% of its total assets.

Acadian Asset Management LLC

Acadian employs a quantitative investment process which is driven by proprietary valuation models that combine a bottom-up view of the attractiveness of individual securities within each market with a top-down view of the attractiveness of each region/industry group, thereby capturing value-added at both the stock and the region/industry levels.

Wellington Management Company, LLP

Wellington Management uses its proprietary global research capabilities to identify stocks for the portfolio. Wellington Management takes a local-regional approach to research and stock selection using a number of different sources to identify purchase candidates, including the firm’s proprietary research, local brokers, and company and local referrals. The sources used depend greatly on the issuer’s region and industry. Long-term investment themes based on general economic factors, along with cost of capital and liquidity forecasts, are important in targeting research efforts.

A candidate for purchase in the portfolio is subjected to extensive fundamental analysis. Wellington Management seeks candidates that exhibit some combination of:

•

a well-articulated business plan,

•

experienced management,

•

a sustainable competitive advantage, and

•

strong financial characteristics.

In addition, valuation analysis, including relevant industry valuations, is used to compare the results to a global and local peer group of companies. Companies that compare favorably with the fundamentals, growth, and valuation characteristics of peers are strong candidates for the portfolio. In implementing purchase decisions, consideration is given to size, liquidity and volatility. Sell decisions are based on changing fundamentals or valuations, or on finding better opportunities for the portfolio. Industry weights are likely to favor sectors in which smaller companies have long-term competitive advantages or are expected to benefit from extended growth opportunities.