SecProbe.io

May 2, 2011
 Terrance J. Lillis Senior Vice President and
Chief Financial Officer
Principal Financial Group, Inc.
711 High Street
Des Moines, Iowa  50392
Re: Principal Financial Group, Inc.
 Form 10-K for the Fiscal Year Ended December 31, 2010
Filed February 16, 2011 File No. 001-16725

Dear Mr. Lillis:
 We have limited our review of your filing to  those issues we have addressed in our
comments.  In our comments, we ask you to provi de us with information to better understand
your disclosure.

Please respond to this letter within te n business days by providing the requested
information or by advising us when you will provide the requested response.  Where a comment
requests you to revise disclosu re, the information you provide s hould show us what the revised
disclosure will look like and identify the annual or quarterly filing, as applicable, in which you
intend to first include it.  If you do not be lieve a comment applies to your facts and
circumstances, please tell us why in your res ponse.  Please furnish us a letter on EDGAR under
the form type label CORRESP that ke ys your responses to our comments.

After reviewing the information provided, we may have additional comments and/or
request that you amend your filing.   Item 7.  Management’s Discussion and Analys is of Financial Condition and Results of
Operations
 Investments

Fixed Maturities Valuation and Credit Quality, page 65

1. For your fixed maturity investments that ar e rated by third party credit rating agencies,
please tell us whether you performed an anal ysis, including consid ering current market
credit spreads, of your investments.   If so, please summarize for us the investments for
which you performed this analysis and the pr ocedures you performed.  Also, where this
analysis resulted in you concluding that the rati ng assigned by the third party credit rating

Terrance J. Lillis
Principal Financial Group, Inc.
 May 2, 2011  Page 2

agency at December 31, 2010 was significantly different, provide us the fair value and
amortized cost of those investments, as we ll as how and why your conclusion differed.
 Item 8.  Financial Statements and Supplementary Data

 Notes to Consolidated Financial Statements

 1.  Nature of Operations and Significant Accounting Policies

Basis of Presentation, page 90

2. You state that “ Investments in LLCs, partnerships and real estate joint ventures in which we
have an ownership percentage of 3% to 5% ar e accounted for under the equity or cost method
depending upon the specific facts and circumstances of our ownership and involvement”.  For
those that you account for at cost, please tell us why you do not use the equity method.
Please refer to ASC 323-30-599-1.  Also, assuming that equity method is not required for
these investments, tell us why you do not accoun t for them at fair value as required by
ASC 944-325-30-1 and 944-325-35-1.
   2.  Investments

Mortgage Loans, page 111

3. You state that you “ac tively monitor and manage our commercial mortgage loan
portfolio. All commercial mortgage loans are analyzed regularly and substantially all are
internally rated, based on a proprietary risk rating cash flow model, in order to monitor
the financial quality of these assets.”  Please revise your disclosure to provide qualitative
information on how those internal risk ratings relate to the likelihood of loss as required
by ASC 310-10-50-30.
12.  Contingencies, Guarantees and Indemnifications

Litigation and Regulatory Contingencies, page 147

4. You state on page 148, “While the outcome of any pending or future litigation or
regulatory matter cannot be predicted, manage ment does not believe that any pending
litigation or regulatory matter will have a ma terial adverse effect on our business or
financial position. The outcome of such ma tters is always uncertain, and unforeseen
results can occur. It is possible that such out comes could materially affect net income in a
particular quarter or annual period.”  We do not believe that  this disclosure meets the
requirements of ASC 450-20-50-3 and 50-4.  Please revise your  disclosure to include an
estimate of the possible loss or range of loss or a statement th at such an estimate cannot
be made for loss contingencies that are at least reasonably po ssible but not accrued, either
because it is not probable that a loss has b een incurred or the amount of loss cannot be
reasonably estimated.

Terrance J. Lillis
Principal Financial Group, Inc.
 May 2, 2011  Page 3

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing include s the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules requir e.  Since the company and its management are
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.
 In responding to our comments, please provi de a written statement from the company
acknowledging that:
 the company is responsible for the adequacy an d accuracy of the disclo sure in the filing;
 staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and
 the company may not assert staff comments as  a defense in any proceeding initiated by
the Commission or any person under the federa l securities laws of  the United States.

Please contact James Peklenk, Staff Account ant, at (202) 551-3661 or Joel Parker,
Accounting Branch Chief, at (202) 551-3651 if you have any questions regarding the comments.
In this regard, do not hesitate to contact me, at (202) 551-3679.

Sincerely,    Jim B. Rosenberg Senior Assistant Chief Accountant