485BPOS
2012-05-31
0000312564
2012-10-01
Dreyfus Municipal Money Market Fund, Inc.
false
2012-09-27
2012-10-01
The fund is non-diversified, which means that a relatively high percentage of the
fund's assets may be invested in a limited number of issuers. Therefore, the
fund's performance may be more vulnerable to changes in the market value of
a single issuer or group of issuers and more susceptible to risks associated with
a single economic, political or regulatory occurrence than a diversified fund.
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<tt>The fund seeks as high a level of current income exempt from federal income tax<br />as is consistent with the preservation of capital and the maintenance of<br />liquidity.</tt>
<tt>The Example is intended to help you compare the cost of investing in the fund<br />with the cost of investing in other mutual funds. The Example assumes that you<br />invest $10,000 in the fund for the time periods indicated and then redeem all of<br />your shares at the end of those periods. The Example also assumes that your<br />investment has a 5% return each year and that the fund's operating expenses<br />remain the same. Although your actual costs may be higher or lower, based on<br />these assumptions your costs would be:</tt>
<tt>As a money market fund, the fund is subject to the maturity, quality, liquidity<br />and diversification requirements of Rule 2a-7 under the Investment Company Act<br />of 1940, as amended, which are designed to help money market funds maintain a<br />stable share price of $1.00. To pursue its goal, the fund normally invests<br />substantially all of its net assets in short-term, high quality municipal<br />obligations that provide income exempt from federal income taxes. The fund may<br />also invest in high quality, short-term structured notes, which are derivative<br />instruments whose value is tied to underlying municipal obligations.<br /> <br />Although the fund seeks to provide income exempt from federal income tax, income<br />from some of the fund's holdings may be subject to the federal alternative<br />minimum tax. In addition, the fund may invest temporarily in high quality,<br />taxable money market instruments, including when the portfolio manager believes<br />acceptable municipal obligations are not available for investment.</tt>
Fund Summary
Example
Investment Objective
The fund's past performance (before and after taxes) is no guarantee of future results.
Principal Risks
Year-by-Year Total Returns as of 12/31 each year (%)
Performance
<tt>For the fund's current yield, call toll-free 1-800-DREYFUS (inside the U.S. only).</tt>
The following bar chart and table provide some indication of the risks of investing in the fund.
<tt>Best Quarter   <br />Q2, 2007: 0.81%<br />Worst Quarter  <br />Q4, 2009: 0.01%<br />                                                                             <br />The fund's year-to-date total return as of 6/30/12 was 0.00%.</tt>
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Average Annual Total Returns as of 12/31/11
<tt>The bar chart shows changes in the performance of the fund's shares from <br />year to year.</tt>
Although the fund seeks to preserve the value of your investment at $1.00 per
share, it is possible to lose money by investing in the fund.
<tt>An investment in the fund is not insured or guaranteed by the Federal Deposit<br />Insurance Corporation (FDIC) or any other government agency. Although the fund<br />seeks to preserve the value of your investment at $1.00 per share, it is<br />possible to lose money by investing in the fund.<br /> <br />The fund's yield will fluctuate as the short-term securities in its portfolio<br />mature and the proceeds are reinvested in securities with different interest<br />rates. Additionally, while the fund has maintained a constant share price since<br />inception, and will continue to try to do so, neither The Dreyfus Corporation<br />nor its affiliates are required to make a capital infusion, enter into a capital<br />support agreement or take other actions to prevent the fund's share price from<br />falling below $1.00. The following are the principal risks that could reduce the<br />fund's income level and/or share price:<br />  <br />o Interest rate risk. This risk refers to the decline in the prices of<br />fixed-income securities that may accompany a rise in the overall level of<br />interest rates. A sharp and unexpected rise in interest rates could cause a<br />money market fund's share price to drop below a dollar.<br /> <br />o Credit risk. Failure of an issuer to make timely interest or principal<br />payments, or a decline or perception of a decline in the credit quality of a<br />security, can cause the security's price to fall, potentially lowering the<br />fund's share price. Although the fund invests only in high quality debt<br />securities, any of the fund's holdings could have its credit rating downgraded<br />or could default. The credit quality of the securities held by the fund can<br />change rapidly in certain market environments, and the default of a single<br />holding could have the potential to cause significant deterioration of the<br />fund's net asset value.<br /> <br />o Liquidity risk. When there is little or no active trading market for specific<br />types of securities, it can become more difficult to sell the securities at or<br />near their perceived value. In such a market, the value of such securities may<br />fall dramatically, potentially lowering the fund's share price, even during<br />periods of declining interest rates. Also, during such periods, redemptions by a<br />few large investors in the fund may have a significant adverse effect on the<br />fund's net asset value and remaining fund shareholders.<br /> <br />o Tax risk. To be tax-exempt, municipal obligations generally must meet certain<br />regulatory requirements. If any such municipal obligation fails to meet these<br />regulatory requirements, the interest received by the fund from its investment<br />in such obligations and distributed to fund shareholders will be taxable.<br /> <br />o Structured notes risk. Structured notes, a type of derivative instrument, can<br />be volatile, and the possibility of default by the financial institution or<br />counterparty may be greater for these instruments than for other types of money<br />market instruments. Structured notes typically are purchased in privately<br />negotiated transactions from financial institutions and, thus, an active trading<br />market for such instruments may not exist.<br /> <br />o Non-diversification risk. The fund is non-diversified, which means that a<br />relatively high percentage of the fund's assets may be invested in a limited<br />number of issuers. Therefore, the fund's performance may be more vulnerable to<br />changes in the market value of a single issuer or group of issuers and more<br />susceptible to risks associated with a single economic, political or regulatory<br />occurrence than a diversified fund.</tt>
Fees and Expenses
Principal Investment Strategy
www.dreyfus.com
<tt>The following bar chart and table provide some indication of the risks of<br />investing in the fund. The table shows the average annual total returns of <br />the fund's shares over time. The fund's past performance (before and after <br />taxes) is no guarantee of future results. More recent performance information <br />may be available at www.dreyfus.com.</tt>
<tt>This table describes the fees and expenses that you may pay if you buy and hold<br />shares of the fund.</tt>
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An investment in the fund is not insured or guaranteed by the Federal Deposit
Insurance Corporation (FDIC) or any other government agency.
DTEXX
0.0099
Worst Quarter
Best Quarter
2012-06-30
65
2007-06-30
205
0.0001
0.0072
0.0005
798
357
0.0317
0.0081
0.0005
0.0014
0.0203
0.0050
2009-12-31
0.0023
0.0110
0.0192
Year-to-date total return
0.0005
0.0056
0.0126
0.0064
0.0293
0.0000
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