Certification Pursuant to Rule 30a-2(b) under the 1940 Act and Section 906 of the

Sarbanes-Oxley Act

I, Robert H. Gordon, President of Driehaus Mutual Funds (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:	March 2, 2012	/s/ Robert H. Gordon
		Robert H. Gordon, President
		(principal executive officer)

I, Michelle L. Cahoon, Vice President and Treasurer of Driehaus Mutual Funds (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:	March 2, 2012	/s/ Michelle L. Cahoon
		Michelle L. Cahoon, Vice President and Treasurer
		(principal financial officer)