NORTHERN INSTITUTIONAL FUNDS

U.S. Government Securities Portfolio

Summary Prospectus   |   April 1, 2010 Ticker: Class A—BUSAX, Class C, Class D—BUSDX

Before you invest, you may want to review the Portfolio’s complete Prospectus, which contains more information about the Portfolio and its risks. You can find the Portfolio’s complete Prospectus and other information about the Portfolio online at www.northernfunds.com/institutional/prospectus. You can also get this information at no cost by calling 800-637-1380 or by sending an e-mail request to northern-funds@ntrs.com. If you purchase shares of the Portfolio through a financial intermediary (such as a bank or a broker-dealer), the complete Prospectus and other information are also available from your financial intermediary. The Portfolio’s complete Prospectus and Statement of Additional Information, both dated April 1, 2010, as supplemented, are incorporated by reference into this summary prospectus and may be obtained, free of charge, at the website, phone number or e-mail address noted above.

INVESTMENT OBJECTIVE

The Portfolio seeks to maximize total return (capital appreciation and income) with minimal reasonable risk.

FEES AND EXPENSES OF THE PORTFOLIO

This table describes the fees and expenses that you may pay if you buy and hold shares of the Portfolio.

Shareholder Fees (fees paid directly from your investment)
None
Annual Portfolio Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Class A	Class C	Class D
Management Fees	0.40%	0.40%	0.40%
Distribution (12b-1) Fees	None	None	None
Other Expenses	0.26%	0.50%	0.65%
Administration Fees	0.10%	0.10%	0.10%
Service Agent Fees	None	0.15%	0.25%
Other Operating Expenses	0.16%	0.25%	0.30%
Total Annual Portfolio Operating Expenses	0.66%	0.90%	1.05%
Fee Waiver and/or Expense Reimbursement(1)	(0.30)%	(0.30)%	(0.30)%
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.36%	0.60%	0.75%

⁽¹⁾ Northern Trust Investments, N.A. (“NTI”) has contractually agreed to waive a portion of its management fees and reimburse certain expenses of the Portfolio. The contractual waiver and reimbursement arrangements are expected to continue until at least April 1, 2011. After this date, NTI or the Portfolio may terminate the contractual arrangements. The Portfolio’s Board of Trustees may terminate the contractual arrangements at any time if it determines that it is in the best interest of the Portfolio and its shareholders.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem 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 Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class A	$37	$181	$338	$794
Class C	$61	$257	$469	$1,080
Class D	$77	$304	$550	$1,255

PORTFOLIO TURNOVER. The Portfolio 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 transaction costs and may result in higher taxes when Portfolio shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s portfolio turnover rate was 1,572.96% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Portfolio will seek capital appreciation and current income in its attempt to maximize total return. In doing so, the Portfolio will invest, under normal circumstances, at least 80% of its net assets in securities issued or guaranteed by the U.S. government or by its agencies, instrumentalities, or sponsored enterprises and repurchase agreements relating to such securities. These may include:

n U.S. Treasury bills, notes and bonds;

n Obligations of the U.S. government or its agencies, instrumentalities or sponsored enterprises, including obligations that are issued by private issuers that are guaranteed as to principal and interest by the U.S. government, its agencies or instrumentalities;

n Mortgage-related securities issued or guaranteed by the U.S. government or by its agencies, instrumentalities or sponsored enterprises;

n Stripped securities evidencing ownership of future interest or principal payments on obligations of the U.S. government or its agencies, instrumentalities or sponsored enterprises; and

n Repurchase agreements relating to the above instruments.

The Portfolio also may make limited investments in the obligations of supranational organizations (such as the World Bank).

SUMMARY PROSPECTUS 1 U.S. GOVERNMENT SECURITIES PORTFOLIO

In buying and selling securities for the Portfolio, the investment management team uses a relative value approach. This approach involves an analysis of general economic and market conditions. It also involves the use of models that analyze and compare expected returns and assumed risks. Under the relative value approach, the investment management team will emphasize particular securities and types of securities (such as treasury, agency, asset-backed and mortgage-related securities) that the team believes will provide a favorable return in light of these risks.

The Portfolio’s dollar-weighted average maturity, under normal circumstances, will range between one and five years.

In seeking to achieve its investment objective, the Portfolio may make significant investments in securities issued by U.S. government-sponsored entities. Obligations issued by U.S. government-sponsored entities are neither issued nor guaranteed by the U.S. Treasury and therefore are not backed by the full faith and credit of the United States.

The investment management team may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Portfolio.

PRINCIPAL RISKS

MARKET RISK is the risk that the market values of fixed-income securities owned by the Portfolio may decline, at times sharply and unpredictably.

MANAGEMENT RISK is the risk that a strategy used by the investment management team may fail to produce the intended results.

LIQUIDITY RISK is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Portfolio would like, adversely affecting the value of the Portfolio’s investments and its returns.

INTEREST RATE/MATURITY RISK is the risk that the value of the Portfolio’s assets will decline because of rising interest rates. This risk is generally higher for the Portfolio than for funds that have shorter-weighted maturities, such as money market funds and short-term bond funds.

PREPAYMENT (OR CALL) RISK is the risk that prepayment of the underlying mortgage or other collateral of some fixed-income securities may result in a decreased rate of return and a decline in value of those securities.

DEBT EXTENSION RISK is the risk that an issuer will exercise its right to pay principal on an obligation held by the Portfolio (such as a mortgage-backed security) later than expected. This may happen during a period of rising interest rates. Under these circumstances, the value of the obligation will decrease and the Portfolio will suffer from the inability to invest in higher yielding securities.

PORTFOLIO TURNOVER RISK is the risk that high portfolio turnover is likely to lead to increased Portfolio expenses that may result in lower investment returns. High portfolio turnover also is likely to result in higher short-term capital gains taxable to shareholders. For the last fiscal year, the annual portfolio turnover rate of the Portfolio exceeded 100%.

U.S. GOVERNMENT SECURITIES RISK is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Many U.S. government securities purchased by the Portfolio are not backed by the full faith and credit of the United States. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future.

As with any mutual fund, it is possible to lose money on an investment in the Portfolio. An investment in the Portfolio is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or Northern Trust Investments, N.A. and The Northern Trust Company.

PORTFOLIO PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing (A) changes in the performance of the Portfolio’s Class A Shares from year to year, and (B) how the average annual total returns of the Portfolio’s outstanding classes of shares compare to those of a broad-based securities market index.

There are no Class C Shares currently outstanding for the Portfolio.

The Portfolio’s past performance, before and after taxes, is not necessarily an indication of how the Portfolio will perform in the future.

Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s Web site at www.northernfunds.com/institutional or by calling 800-637-1380.

CALENDAR YEAR TOTAL RETURN (CLASS A)*

*For the periods shown in the bar chart above, the highest quarterly return was 4.98% in the fourth quarter of 2008, and the lowest quarterly return was (1.74)% in the second quarter of 2004.

U.S. GOVERNMENT SECURITIES PORTFOLIO 2 SUMMARY PROSPECTUS

AVERAGE ANNUAL TOTAL RETURNS

(For the periods ended December 31, 2009)

	Inception Date	1-Year	5-Year	10-Year	Since Inception
Class A
Return before taxes	4/5/93	1.61%	4.35%	4.96%	5.00%
Return after taxes on distributions		0.13%	2.93%	3.31%	3.12%
Return after taxes on distributions and sale of Portfolio shares		1.06%	2.88%	3.26%	3.11%
Class D return before taxes	9/15/94	1.51%	4.00%	4.59%	4.64%
Barclays Capital 1-5 Year U.S. Government Index (reflects no deduction for fees, expenses, or taxes)		0.98%	4.50%	5.14%	5.24%

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown only for Class A Shares. After-tax returns for other classes will vary.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemption are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns After Taxes on Distributions and Sale of Portfolio Shares to be greater than the Returns After Taxes on Distributions or even the Returns Before Taxes.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGER. Northern Trust Investments, N.A., a subsidiary of The Northern Trust Company, serves as the investment adviser of the Portfolio. Daniel J. Personette, Vice President of Northern Trust Investments, N.A., has been manager of the Portfolio since November 2006.

PURCHASE AND SALE OF PORTFOLIO SHARES

You may purchase Portfolio shares through your institutional account at Northern Trust (or an affiliate) or an authorized intermediary or you may open an account directly with Northern Institutional Funds (the “Trust”) with a minimum initial investment of $5 million in one or more of the Trust’s portfolios. There is no minimum for subsequent investments.

On any business day, you may sell (redeem) or exchange shares through your institutional account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

n By Mail – Send a written request to: Northern Institutional Funds, P.O. Box 75986, Chicago, Illinois 60675-5986.

n By Telephone – Call the Northern Institutional Funds Center at 800-637-1380 for instructions.

n By Wire – Authorize wire redemptions on your New Account Application and have proceeds sent by federal wire transfer to a previously designated bank account (the minimum redemption amount by this method is $10,000).

TAX INFORMATION

The Portfolio’s distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Portfolio through a broker-dealer or other financial intermediary (such as a bank), the Portfolio and its related companies may pay the intermediary for the sale of Portfolio shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Portfolio over another investment. Ask your salesperson or visit your financial intermediary’s Web site for more information.

SUMMARY PROSPECTUS 3 U.S. GOVERNMENT SECURITIES PORTFOLIO

U.S. GOVERNMENT SECURITIES PORTFOLIO 4 SUMMARY PROSPECTUS NIF SUM USGS