Diversified International Fund (Prospectus Summary): | Diversified International Fund

DIVERSIFIED INTERNATIONAL FUND    

Supplement dated June 16, 2011

to the Class A, Class B, and Class C Prospectus

for Principal Funds, Inc.

dated March 1, 2011

(as supplemented on March 14, 2011 and March 15, 2011)  

This supplement updates information currently in the Prospectus. Retain this supplement with the  

Prospectus.  

Add the following under the Performance heading, just above the Total Returns as of December 31 each  

year heading:  

Effective June 30, 2011, the benchmark will change. The Investment Advisor and Sub-Advisor believe the  

MSCI EAFE Index NDTR D is more widely used for funds in the foreign large blend category than the  

MSCI ACWI Ex-US Index.  

Add the following to the Average Annual Total Returns table:   

Average Annual Total Returns	Average Annual Returns, Label	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years
MSCI EAFE Index NDTR D Diversified International Fund	MSCI EAFE Index NDTR D (reflects no deduction for fees, expenses, or taxes)	7.75%	2.46%	3.50%