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

I, Richard H. Driehaus, 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: December 4, 2009	/s/ Richard H. Driehaus
	Richard H. Driehaus, 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: December 4, 2009	/s/ Michelle L. Cahoon
	Michelle L. Cahoon, Vice President and
	Treasurer (principal financial officer)