SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

__________________

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report:  January 16, 2013

(Date of earliest event reported)

PRINCIPAL FINANCIAL GROUP, INC.

(Exact name of registrant as specified in its charter)

                                                                           Delaware                          1-16725                                42-1520346

                                                           (State or other jurisdiction        (Commission file number)            (I.R.S. Employer

                                                                     of incorporation)                                                               Identification Number)

711 High Street, Des Moines, Iowa 50392

(Address of principal executive offices)

(515) 247-5111

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[     ]     Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[     ]     Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[     ]     Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act

(17 CFR 240.14d-2(b))

[     ]     Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act

(17 CFR 240.13e-4(c))

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Item 7.01        Regulation FD Disclosure

This report is filed quarterly to disclose assets under management (“AUM”) by asset manager, prior to the availability of Principal Financial Group, Inc.'s (the "Company") quarterly earnings release. The amounts presented herein will be consistent with the format of AUM by asset manager and presented again in such format within the Company's financial supplement for the quarter ended December 31, 2012 when that document is posted to the Company's investor relations web site on or about January 31, 2013. AUM may include assets managed directly and pursuant to dual employment agreements among affiliated companies.  

As of December 31, 2012, the assets under management by asset manager were $263.2  billion for Principal Global Investors and $66.9 billion for Principal International.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

                                                                                                                PRINCIPAL FINANCIAL GROUP, INC.

                                                                                                                By:          /s/ John Egan                                     

                                                                                                                Name:  John Egan

                                        Title:    Vice President – Investor Relations

Date:   January 16, 2013