Opportunistic Municipal Fund (Prospectus Summary) | Opportunistic Municipal Fund

Opportunistic Municipal Fund

Objective:

The Fund seeks to provide a high level of income that is exempt from federal income
tax while protecting investors' capital.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold
shares of the Fund. You may qualify for sales charge discounts if you and your
family invest, or agree to invest in the future, at least $100,000 in Principal
Funds, Inc. More information about these and other discounts is available from
your financial professional and in "Choosing a Share Class and The Costs of
Investing" beginning on page 38 of the Fund's prospectus and "Multiple Class
Structure" beginning on page 59 of the Fund's Statement of Additional
Information.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Opportunistic Municipal Fund	Class A	Class C
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	3.75%	none
Maximum Deferred Sales Charge (Load) (as a percentage of dollars subject to charge)	1.00%	1.00%

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Opportunistic Municipal Fund		Class A	Class C
Management Fees		0.50%	0.50%
Distribution and/or Service (12b-1) Fees		0.25%	1.00%
Other Expenses	[1][2]	0.51%	0.54%
Total Annual Fund Operating Expenses		1.26%	2.04%
Expense Reimbursement	[3]	0.29%	0.32%
Total Annual Fund Operating Expenses after Expense Reimbursement		0.97%	1.72%

Example

This Example is intended to help you compare the cost of investing in the Fund
with the cost of investing in other mutual funds.
  
The Example assumes that you invest $10,000 in the Fund for the time periods
indicated and then redeem all of your shares at the end of those periods. The
Example also assumes that your investment has a 5% return each year and that the
Fund's operating expenses remain the same. Although your actual costs may be
higher or lower, based on these assumptions your costs would be:

Expense Example Opportunistic Municipal Fund (USD $)	Expense Example, With Redemption, 1 Year	Expense Example, With Redemption, 3 Years
Class A	470	732
Class C	275	609

You would pay the following expenses if you did not redeem your shares:

Expense Example, No Redemption Opportunistic Municipal Fund (USD $)	Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years
Class A	470	732
Class C	175	609

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells
securities (or "turns over" its portfolio). A higher portfolio turnover rate
may indicate higher transaction costs and may result in higher taxes when Fund
shares are held in a taxable account. These costs, which are not reflected in
annual fund operating expenses or in the example, affect the Fund's performance.
This is a new Fund and does not yet have a portfolio turnover rate to disclose.

Principal Investment Strategies

Under normal circumstances, the Fund invests at least 80% of its net assets,
plus borrowings for investment purposes, in municipal obligations (securities
issued by or on behalf of state or local governments and other public
authorities). Municipal obligations pay interest that is exempt from federal
income tax. The Fund has a flexible investment strategy and may invest in
obligations of any duration and credit quality, including below investment grade
bonds (rated at the time of purchase Ba1 or lower by Moody's or BB+ or lower by
S&P, sometimes called "junk bonds") as rated by at least one independent rating
agency, or if unrated, judged to be of comparable quality by the Fund's
Sub-Advisor.

The Fund may invest in other debt obligations, including (but not limited to)
taxable municipal obligations, U.S. Treasury securities, obligations of the U.S.
Government, its agencies and instrumentalities ("Agency Securities") and inverse
floating rate obligations, which are generally more volatile than other types of
municipal obligations. The Fund may invest in exchange-traded funds (ETFs) to
gain exposure to the municipal market.

The Fund may purchase derivative instruments, which derive their value from
another instrument, security or index. The Fund may purchase or sell various
kinds of financial futures contracts to hedge against changes in interest rates
or as a substitute for the purchase of portfolio securities. The Fund also may
enter into interest rate swaps and credit derivatives, which may include credit
default swaps.

Principal Risks

The Fund may be an appropriate investment for investors who are seeking monthly,
federally tax-exempt dividends to produce income or to reinvest for modest
growth and are willing to accept fluctuations in the value of their investment.

The value of your investment in the Fund changes with the value of the Fund's
investments. Many factors affect that value, and it is possible to lose money by
investing in the Fund. An investment in the Fund is not a deposit of a bank and
is not insured or guaranteed by the Federal Deposit Insurance Corporation or any
other government agency. The principal risks of investing in the Fund, in
alphabetical order, are:
  
Counterparty Risk. Counterparty risk is the risk that the counterparty to a
derivatives contract or repurchase agreement, the borrower of a portfolio's
securities, or other obligation, will be unable or unwilling to make timely
principal, interest, or settlement payments, or otherwise to honor its
obligations.
  
Derivatives Risk. Transactions in derivatives (such as options, futures,
currency contracts, and swaps) may increase volatility, cause the liquidation of
portfolio positions when not advantageous to do so and produce disproportionate
losses.

Exchange-Traded Funds ("ETFs") Risk. An ETF is subject to the risks associated
with direct ownership of the securities comprising the index on which the ETF is
based. Fund shareholders indirectly bear their proportionate share of the
expenses of the ETFs in which the fund invests.
  
Fixed-Income Securities Risk. Fixed-income securities are subject to interest
rate risk and credit quality risk. The market value of fixed-income securities
generally declines when interest rates rise, and an issuer of fixed-income
securities could default on its payment obligations.
  
High Yield Securities Risk. High yield fixed-income securities (commonly
referred to as "junk bonds") are subject to greater credit quality risk than
higher rated fixed-income securities and should be considered speculative.
  
Inverse Floating Rate Investments. Inverse floating rate investments are
extremely sensitive to changes in interest rates and in some cases their market
value may be extremely volatile.

Leverage Risk. Leverage created by borrowing or certain types of transactions or
investments, such as reverse repurchase agreements, loans of portfolio securities,
and the use of when-issued, delayed delivery or forward commitment transactions,
or derivative instruments, may impair the fund's liquidity, cause it to liquidate
positions at an unfavorable time, increase volatility of the fund's net asset value,
or diminish the fund's performance.
  
Municipal Securities Risk. Principal and interest payments on municipal
securities may not be guaranteed by the issuing body and may be payable only
from a particular source. That source may not perform as expected and payment
obligations may not be made or made on time.
  
Portfolio Duration Risk. Portfolio duration is a measure of the expected life of
a fixed-income security and its sensitivity to changes in interest rates. The
longer a fund's average portfolio duration, the more sensitive the fund will be
to changes in interest rates.

U.S. Government Securities Risk. Yields available from U.S. government
securities are generally lower than yields from many other fixed-income
securities.
  
U.S. Government Sponsored Securities Risk. Securities issued by U.S.
government-sponsored or -chartered enterprises such as the Federal Home Loan
Mortgage Corporation, the Federal National Mortgage Association, and the Federal
Home Loan Banks are not issued or guaranteed by the U.S. Treasury.

Performance

No performance information is shown because the Fund has not yet had a calendar
year of performance. The Fund's performance will be benchmarked against the
Barclays Capital Municipal Bond Index.

[1] Other Expenses are estimated for the year ending August 31, 2012.

[2] Other Expenses include: Interest Expense 0.07%

[3] Principal Management Corporation ("Principal"), the investment advisor, has contractually agreed to limit the Fund's expenses attributable to Class A and Class C shares and, if necessary, pay expenses normally payable by the Fund, excluding interest expense through the period ending December 31, 2013. The expense limit will maintain a total level of operating expenses (expressed as a percent of average net assets on an annualized basis) not to exceed 0.90% for Class A and 1.65% for Class C shares. It is expected that the expense limit will continue through the period disclosed; however, Principal Funds, Inc. and Principal, the parties to the agreement, may agree to terminate the expense limit prior to the end of the period.