485BPOS

As filed with the U.S. Securities and Exchange Commission
on September 28, 2012

Securities Act File No. 33-92982

Investment Company Act File No. 811-9054

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	x
Pre-Effective Amendment No.	o
Post-Effective Amendment No. 47	x
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT of 1940	x
Amendment No. 48	x

(Check appropriate box or boxes)

Credit Suisse Opportunity Funds

(Exact name of registrant as specified in charter)

One Madison Avenue, New York, New York	10010
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s Telephone Number, Including Area Code: (212) 325-2000

Karen Regan

Credit Suisse Opportunity Funds

One Madison Avenue

New York, New York 10010

(Name and Address of Agent for Service)

Copy to:

Rose F. DiMartino, Esq.
Willkie Farr & Gallagher LLP
787 Seventh Avenue
New York, New York 10019-6099

Approximate date of proposed public offering:

It is proposed that this filing will become effective (check appropriate box)

x Immediately upon filing pursuant to paragraph (b)

o on (date) pursuant to paragraph (b)

o 60 days after filing pursuant to paragraph (a) (1)

o on (date) pursuant to paragraph (a) (1)

o 75 days after filing pursuant to paragraph (a) (2), or

o on (date) pursuant to paragraph (a) (2) of Rule 485

If appropriate, check the following box:

o This post-effective amendment designates a new effective date for a previously filed post-effective amendment

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirement for effectiveness of this registration statement under rule 485(b) under the Securities Act and has duly caused this Amendment to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of New York and the State of New York, on the 28th day of September 2012.

CREDIT SUISSE OPPORTUNITY FUNDS
By:	/s/ John G. Popp
	John G. Popp
	Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, as amended, this Amendment has been signed below by the following persons in the capacities and on the date indicated:

SIGNATURE	TITLE	DATE
/s/ John G. Popp	Chief Executive Officer	September 28, 2012
John G. Popp
/s/ Thomas M. Sipp	Chief Financial Officer	September 28, 2012
Thomas M. Sipp
/s/ Steven N. Rappaport*	Chairman of the Board	September 28, 2012
Steven N. Rappaport
/s/ Jeffrey E. Garten*	Trustee	September 28, 2012
Jeffrey E. Garten
/s/ Peter F. Krogh*	Trustee	September 28, 2012
Peter F. Krogh
/s/ Enrique R. Arzac*	Trustee	September 28, 2012
Enrique R. Arzac

*By:	/s/ Karen Regan
	Karen Regan, as Attorney-in-Fact

2

EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund

CREDIT SUISSE STRATEGIC INCOME FUND

INVESTMENT OBJECTIVE

The fund seeks total return.

FEES AND FUND EXPENSES

The accompanying tables describe 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 $50,000 in Credit Suisse Funds. More
information about these and other discounts is available from your financial
representative and in this Prospectus on page 48 under the heading "Other
Shareholder Information - Class A and C Shares and Sales Charges" and in the
fund's Statement of Additional Information ("SAI") on page 39 under the heading
"Additional Purchase and Redemption Information."

Shareholder fees (paid directly from your investment)

Shareholder Fees Credit Suisse Strategic Income Fund	Class A		Class C		Class I
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	4.75%		none		none
Maximum deferred sales charge (load) (as a percentage of the lesser of original purchase price or redemption proceeds, as applicable)	none	[1]	1.00%	[2]	none
Maximum sales charge (load) on reinvested distributions (as a percentage of offering price)	none		none		none
Redemption or exchange fees (as a percentage of net asset value on date of redemption or exchange) (for shares redeemed or exchanged within 30 days from the date of purchase)	2.00%		2.00%		2.00%

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Credit Suisse Strategic Income Fund		Class A	Class C	Class I
Management fee		0.75%	0.75%	0.75%
Distribution and service (12b-1) fee		0.25%	1.00%	none
Other expenses	[1]	1.16%	1.16%	1.16%
Total annual fund operating expenses		2.16%	2.91%	1.91%
Less: amount of fee limitations/expense reimbursements	[2]	0.92%	0.92%	0.92%
Total annual fund operating expenses after fee limitations/expense reimbursements		1.24%	1.99%	0.99%

EXAMPLE

This example may help you compare the cost of investing in the fund with the
cost of investing in other mutual funds.

Assume you invest $10,000, the fund returns 5% annually, expense ratios remain
the same and you close your account at the end of each of the time periods
shown. Based on these assumptions, your cost would be:

Expense Example Credit Suisse Strategic Income Fund (USD $)	Expense Example, with Redemption, 1 Year	Expense Example, with Redemption, 3 Years
Class A	595	1,034
Class C	302	814
Class I	101	511

Expense Example, No Redemption Credit Suisse Strategic Income Fund (USD $)	Expense Example, No Redemption, 1 Year	Expense Example, No Redemption, 3 Years
Class A	595	1,034
Class C	202	814
Class I	101	511

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 may
indicate higher transaction costs. These costs, which are not reflected in
annual fund operating expenses or in the example, affect the fund's performance.
The fund's annual rate of portfolio turnover for its first year of operations is
anticipated to be approximately 100%, but may be lower or higher.

PRINCIPAL INVESTMENT STRATEGIES

The fund pursues its investment objective of total return by investing in a
broad range of debt instruments. "Strategic" in the fund's name means that
the fund seeks both current income and capital appreciation as elements of
total return. The debt instruments in which the fund may invest include:

o bonds and other debt instruments issued by domestic and foreign companies
  of any size (including below investment grade debt securities (commonly known
  as "junk bonds"));

o senior secured floating rate loans ("Senior Loans");

o mortgage-backed securities, asset-backed securities and collateralized loan
  obligations (CLOs);

o convertible debt securities;

o obligations issued by foreign governments; and

o obligations issued by the U.S. government and its agencies or instrumentalities
  (such as U.S. Treasury securities or Treasury inflation protected securities).

In seeking to achieve its investment objective, the fund adjusts its portfolio's
exposure amongst the various types of debt instruments based on market conditions
and outlook. At any given time, the fund may have a substantial weighting in any
one asset class. Accordingly, the fund will, at times, be invested in debt
instruments of various credit qualities and maturities, while at other times, the
fund may emphasize one particular credit quality or maturity.

The fund's investment adviser and sub-adviser emphasize bottom-up fundamental
credit analysis and top-down macroeconomic analysis, combined with a focused
relative value approach, and are not constrained by any particular duration or
credit quality targets. The fund's allocation among various debt instruments
will be made on the basis of the portfolio managers' assessment of opportunities
for total return relative to the risk of each type of investment. The fund may
also take temporary defensive positions in cash and short-term bonds from time
to time.

The fund may invest significantly in below investment grade debt securities and
is authorized to invest without limit in these securities. Below investment
grade debt securities are rated in the lower rating categories of the established
rating services (Ba or lower by Moody's Investor Service, Inc. ("Moody's") and BB
or lower by Standard & Poor's, a division of The McGraw Hill Companies ("S&P")),
or, if unrated, are deemed by the fund's investment adviser or sub-adviser to be
of comparable quality.

The fund may invest in non-U.S. dollar denominated debt instruments. The fund
may utilize foreign currency transactions, including currency options and
forward foreign currency contracts, to hedge non-U.S. dollar investments or to
establish or adjust exposure to particular foreign securities, markets or
currencies, but it is not required to do so.  

The fund may take short positions in securities or indices and generally will do
so by using swaps or futures. For example, the fund may enter into a futures
contract pursuant to which it agrees to sell an asset (that it does not currently
own) at a specified price at a specified point in the future. This gives the fund
a short position with respect to that asset. The fund will benefit to the extent
the asset decreases in value (and will be harmed to the extent the asset increases
in value) between the time it enters into the futures contract and the agreed date
of sale.

PRINCIPAL RISKS OF INVESTING IN THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the
possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest,
please make sure you understand the risks that apply to the fund. As with
any mutual fund, you could lose money over any period of time.

Investments in the fund are not bank deposits and are not insured or guaranteed
by the Federal Deposit Insurance Corporation or any other government agency.

BELOW INVESTMENT GRADE SECURITIES RISK

Below investment grade securities are regarded as being predominantly speculative
as to the issuer's ability to make payments of principal and interest. Investment
in such securities involves substantial risk. Issuers of below investment grade
securities may be highly leveraged and may not have available to them more
traditional methods of financing. Therefore, the risks associated with acquiring
the securities of such issuers generally are greater than is the case with
higher-rated securities.

COLLATERALIZED LOAN OBLIGATIONS RISK

CLOs are subject to the risk of substantial losses due to actual defaults,
decrease of market value due to collateral defaults and disappearance of
subordinate tranches, market anticipation of defaults, and investor aversion to
CLO securities as a class. The risks of CLOs depend largely on the type of the
underlying loans and the tranche of CLOs in which the fund invests. In addition,
CLOs carry risks including interest rate risk and credit risk.

CONFLICT OF INTEREST RISK

Affiliates of Credit Suisse may act as underwriter, lead agent or administrative
agent for loans and participate in the secondary market for loans. Because of
limitations imposed by applicable law, the presence of Credit Suisse's affiliates
in the primary and secondary markets for loans may restrict the fund's ability to
acquire some loans or affect the timing or price of such acquisitions.

CONVERTIBLE SECURITIES RISK

The market value of a convertible security performs like that of a regular debt
security; that is, if market interest rates rise, the value of a convertible
security usually falls. In addition, convertible securities are subject to the
risk that the issuer will not be able to pay interest or dividends when due, and
their market value may change based on changes in the issuer's credit rating or
the market's perception of the issuer's creditworthiness. Since it derives a
portion of its value from the common stock into which it may be converted, a
convertible security is also subject to the same types of market and issuer
risks that apply to the underlying common stock.
  
CREDIT RISK

The issuer of a security, the borrower of a loan or the counterparty to a
contract, including derivatives contracts, may default or otherwise become
unable to honor a financial obligation. Changes in an issuer's credit rating or
the market's perception of an issuer's creditworthiness also may affect the
value of the fund's investment in that issuer.

DERIVATIVES RISK

Derivatives are financial contracts whose value depends on, or is derived from,
the value of an underlying asset, instrument or index. The fund may use
derivatives as part of a strategy designed to reduce exposure to certain risks,
such as currency risk. Derivatives are subject to a number of risks described
elsewhere in this Prospectus, such as interest rate risk, market risk and credit
risk. Also, suitable derivative transactions may not be available in all
circumstances and there can be no assurance that the fund will engage in these
transactions to reduce exposure to other risks when that would be beneficial.

EXTENSION RISK

An unexpected rise in interest rates may extend the life of a mortgage-backed
security beyond the expected prepayment time, typically reducing the security's
value.

FOREIGN SECURITIES RISK

A fund that invests outside the U.S. carries additional risks that include:

o Currency Risk Fluctuations in exchange rates between the U.S. dollar and
  foreign currencies may negatively affect an investment. Adverse changes in
  exchange rates may erode or reverse any gains produced by
  foreign-currency-denominated investments and may widen any losses. The fund may,
  but is not required to, seek to reduce currency risk by hedging part or all of
  its exposure to various foreign currencies.

o Information Risk Key information about an issuer, security or market may be
  inaccurate or unavailable.

o Political Risk Foreign governments may expropriate assets, impose capital or
  currency controls, impose punitive taxes, or nationalize a company or industry.
  Any of these actions could have a severe effect on security prices and impair
  the fund's ability to bring its capital or income back to the U.S. Other
  political risks include economic policy changes, social and political instability,
  military action and war.

FUTURES CONTRACTS RISK

The risks associated with the fund's use of futures contracts include the risk
that: (i) changes in the price of a futures contract may not always track the
changes in market value of the underlying reference asset; (ii) trading
restrictions or limitations may be imposed by an exchange, and government
regulations may restrict trading in futures contracts; and (iii) if the fund has
insufficient cash to meet margin requirements, the fund may need to sell other
investments, including at disadvantageous times.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an
investment. With bonds and other debt instruments, a rise in interest rates
typically causes a fall in values, while a fall in interest rates typically
causes a rise in values. Generally, the longer the maturity or duration of a
debt instrument, the greater the impact of a change in interest rates on the
instrument's value.

LIQUIDITY RISK

Certain portfolio holdings may be difficult or impossible to sell at the time
and the price that the fund would like. The fund may have to lower the price,
sell other holdings instead or forgo an investment opportunity. Any of these
could have a negative effect on portfolio management or performance.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and
unpredictably. These fluctuations, which are often referred to as "volatility,"
may cause an instrument to be worth less than it was worth at an earlier time.
Market risk may affect a single issuer, industry, sector of the economy, or the
market as a whole. Market risk is common to most investments - including stocks,
bonds and fixed income instruments, and the mutual funds that invest in them.

MORTGAGE- AND ASSET-BACKED SECURITIES RISKS

The value of the fund's mortgage-backed securities can fall if the owners of the
underlying mortgages pay off their mortgages sooner than expected, which could
happen when interest rates fall, or later than expected, which could happen when
interest rates rise. If the underlying mortgages are paid off sooner than
expected, the fund may have to reinvest this money in mortgage-backed or other
securities that have lower yields.

Payment of interest and repayment of principal may be impacted by the cash flows
generated by the assets backing asset-backed securities. The value of the fund's
asset-backed securities may also be affected by changes in interest rates, the
availability of information concerning the interests in and structure of the
pools of purchase contracts, financing leases or sales agreements that are
represented by these securities, the creditworthiness of the servicing agent for
the pool, the originator of the loans or receivables, or the entities that
provide any supporting letters of credit, surety bonds, or other credit
enhancements.
  
PREPAYMENT RISK

In a declining interest rate environment, prepayment of loans and other fixed
income instruments with high stated interest rates may increase. In such
circumstances, the fund may have to reinvest the prepayment proceeds at lower
yields.

SENIOR LOANS RISKS

Senior Loans are subject to the risk that a court could subordinate a Senior
Loan, which typically holds the most senior position in the issuer's capital
structure, to presently existing or future indebtedness or take other action
detrimental to the holders of Senior Loans. Senior Loans are also subject to
heightened prepayment risk, as they usually have mandatory and optional
prepayment provisions. Senior Loans are subject to the risk that the value of
the collateral, if any, securing a loan may decline, be insufficient to meet
the obligations of the borrower, or be difficult to liquidate.

SHORT POSITION RISK

The fund may enter into a short position through a futures contract or swap
agreement. Taking short positions involves leverage of the fund's assets and
presents various risks. If the price of the asset, instrument or market on which
the fund has taken a short position increases, then the fund will incur a loss
equal to the increase in price from the time that the short position was entered
into plus any premiums and interest paid to a third party. Therefore, taking
short positions involves the risk that losses may be exaggerated, potentially
losing more money than the actual cost of the investment. The fund's loss on a
short sale could theoretically be unlimited in a case where the fund is unable,
for whatever reason, to close out its short position.

VALUATION RISK

The lack of an active trading market may make it difficult to obtain an accurate
price for an instrument held by the fund. Many derivative instruments are not
actively traded.

PERFORMANCE SUMMARY

Because the fund is new, no performance information is available as of the date
of this Prospectus.

The fund makes updated performance information available at the fund's website
(www.credit-suisse.com/us/funds) or by calling Credit Suisse Funds at
877-870-2874.

[1] Purchases of shares of $1,000,000 or more may be subject to a 0.50% deferred sales charge on redemptions within 12 months of purchase.

[2] 1% during the first year.

[1] "Other expenses" have been estimated for the fund's first year of operations.

[2] Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.24% of the fund's average daily net assets for Class A shares, 1.99% of the fund's average daily net assets for Class C shares and 0.99% of the fund's average daily net assets for Class I shares at least through the fund's first year of operations (the fund has not yet begun operations). The Trust is authorized to reimburse Credit Suisse for management fees previously limited and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursements must be paid at a date not more than three years after the end of the fund's first year of operations and the reimbursements do not cause a class to exceed the applicable expense limitation in the contract at the time the fees were limited or expenses are paid. This contract may not be terminated before the end of the fund's first year of operations.

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Label	Element	Value
Risk Return [Abstract]	rr_RiskReturnAbstract
ProspectusDate	rr_ProspectusDate	Sep. 18, 2012
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund
Risk Return [Abstract]	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	CREDIT SUISSE STRATEGIC INCOME FUND
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The fund seeks total return.
Expense [Heading]	rr_ExpenseHeading	FEES AND FUND EXPENSES
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The accompanying tables describe 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 $50,000 in Credit Suisse Funds. More information about these and other discounts is available from your financial representative and in this Prospectus on page 48 under the heading "Other Shareholder Information - Class A and C Shares and Sales Charges" and in the fund's Statement of Additional Information ("SAI") on page 39 under the heading "Additional Purchase and Redemption Information."
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. The fund's annual rate of portfolio turnover for its first year of operations is anticipated to be approximately 100%, but may be lower or higher.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	100.00%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Credit Suisse Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	"Other expenses" have been estimated for the fund's first year of operations.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example may help you compare the cost of investing in the fund with the cost of investing in other mutual funds. Assume you invest $10,000, the fund returns 5% annually, expense ratios remain the same and you close your account at the end of each of the time periods shown. Based on these assumptions, your cost would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The fund pursues its investment objective of total return by investing in a broad range of debt instruments. "Strategic" in the fund's name means that the fund seeks both current income and capital appreciation as elements of total return. The debt instruments in which the fund may invest include: o bonds and other debt instruments issued by domestic and foreign companies   of any size (including below investment grade debt securities (commonly known   as "junk bonds")); o senior secured floating rate loans ("Senior Loans"); o mortgage-backed securities, asset-backed securities and collateralized loan   obligations (CLOs); o convertible debt securities; o obligations issued by foreign governments; and o obligations issued by the U.S. government and its agencies or instrumentalities   (such as U.S. Treasury securities or Treasury inflation protected securities). In seeking to achieve its investment objective, the fund adjusts its portfolio's exposure amongst the various types of debt instruments based on market conditions and outlook. At any given time, the fund may have a substantial weighting in any one asset class. Accordingly, the fund will, at times, be invested in debt instruments of various credit qualities and maturities, while at other times, the fund may emphasize one particular credit quality or maturity. The fund's investment adviser and sub-adviser emphasize bottom-up fundamental credit analysis and top-down macroeconomic analysis, combined with a focused relative value approach, and are not constrained by any particular duration or credit quality targets. The fund's allocation among various debt instruments will be made on the basis of the portfolio managers' assessment of opportunities for total return relative to the risk of each type of investment. The fund may also take temporary defensive positions in cash and short-term bonds from time to time. The fund may invest significantly in below investment grade debt securities and is authorized to invest without limit in these securities. Below investment grade debt securities are rated in the lower rating categories of the established rating services (Ba or lower by Moody's Investor Service, Inc. ("Moody's") and BB or lower by Standard & Poor's, a division of The McGraw Hill Companies ("S&P")), or, if unrated, are deemed by the fund's investment adviser or sub-adviser to be of comparable quality. The fund may invest in non-U.S. dollar denominated debt instruments. The fund may utilize foreign currency transactions, including currency options and forward foreign currency contracts, to hedge non-U.S. dollar investments or to establish or adjust exposure to particular foreign securities, markets or currencies, but it is not required to do so.   The fund may take short positions in securities or indices and generally will do so by using swaps or futures. For example, the fund may enter into a futures contract pursuant to which it agrees to sell an asset (that it does not currently own) at a specified price at a specified point in the future. This gives the fund a short position with respect to that asset. The fund will benefit to the extent the asset decreases in value (and will be harmed to the extent the asset increases in value) between the time it enters into the futures contract and the agreed date of sale.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS OF INVESTING IN THE FUND
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	A WORD ABOUT RISK All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money. Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time. Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. BELOW INVESTMENT GRADE SECURITIES RISK Below investment grade securities are regarded as being predominantly speculative as to the issuer's ability to make payments of principal and interest. Investment in such securities involves substantial risk. Issuers of below investment grade securities may be highly leveraged and may not have available to them more traditional methods of financing. Therefore, the risks associated with acquiring the securities of such issuers generally are greater than is the case with higher-rated securities. COLLATERALIZED LOAN OBLIGATIONS RISK CLOs are subject to the risk of substantial losses due to actual defaults, decrease of market value due to collateral defaults and disappearance of subordinate tranches, market anticipation of defaults, and investor aversion to CLO securities as a class. The risks of CLOs depend largely on the type of the underlying loans and the tranche of CLOs in which the fund invests. In addition, CLOs carry risks including interest rate risk and credit risk. CONFLICT OF INTEREST RISK Affiliates of Credit Suisse may act as underwriter, lead agent or administrative agent for loans and participate in the secondary market for loans. Because of limitations imposed by applicable law, the presence of Credit Suisse's affiliates in the primary and secondary markets for loans may restrict the fund's ability to acquire some loans or affect the timing or price of such acquisitions. CONVERTIBLE SECURITIES RISK The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer's credit rating or the market's perception of the issuer's creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock.    CREDIT RISK The issuer of a security, the borrower of a loan or the counterparty to a contract, including derivatives contracts, may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer. DERIVATIVES RISK Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, instrument or index. The fund may use derivatives as part of a strategy designed to reduce exposure to certain risks, such as currency risk. Derivatives are subject to a number of risks described elsewhere in this Prospectus, such as interest rate risk, market risk and credit risk. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that the fund will engage in these transactions to reduce exposure to other risks when that would be beneficial. EXTENSION RISK An unexpected rise in interest rates may extend the life of a mortgage-backed security beyond the expected prepayment time, typically reducing the security's value. FOREIGN SECURITIES RISK A fund that invests outside the U.S. carries additional risks that include: o Currency Risk Fluctuations in exchange rates between the U.S. dollar and   foreign currencies may negatively affect an investment. Adverse changes in   exchange rates may erode or reverse any gains produced by   foreign-currency-denominated investments and may widen any losses. The fund may,   but is not required to, seek to reduce currency risk by hedging part or all of   its exposure to various foreign currencies. o Information Risk Key information about an issuer, security or market may be   inaccurate or unavailable. o Political Risk Foreign governments may expropriate assets, impose capital or   currency controls, impose punitive taxes, or nationalize a company or industry.   Any of these actions could have a severe effect on security prices and impair   the fund's ability to bring its capital or income back to the U.S. Other   political risks include economic policy changes, social and political instability,   military action and war. FUTURES CONTRACTS RISK The risks associated with the fund's use of futures contracts include the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying reference asset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts; and (iii) if the fund has insufficient cash to meet margin requirements, the fund may need to sell other investments, including at disadvantageous times. INTEREST RATE RISK Changes in interest rates may cause a decline in the market value of an investment. With bonds and other debt instruments, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest rates on the instrument's value. LIQUIDITY RISK Certain portfolio holdings may be difficult or impossible to sell at the time and the price that the fund would like. The fund may have to lower the price, sell other holdings instead or forgo an investment opportunity. Any of these could have a negative effect on portfolio management or performance. MARKET RISK The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, sector of the economy, or the market as a whole. Market risk is common to most investments - including stocks, bonds and fixed income instruments, and the mutual funds that invest in them. MORTGAGE- AND ASSET-BACKED SECURITIES RISKS The value of the fund's mortgage-backed securities can fall if the owners of the underlying mortgages pay off their mortgages sooner than expected, which could happen when interest rates fall, or later than expected, which could happen when interest rates rise. If the underlying mortgages are paid off sooner than expected, the fund may have to reinvest this money in mortgage-backed or other securities that have lower yields. Payment of interest and repayment of principal may be impacted by the cash flows generated by the assets backing asset-backed securities. The value of the fund's asset-backed securities may also be affected by changes in interest rates, the availability of information concerning the interests in and structure of the pools of purchase contracts, financing leases or sales agreements that are represented by these securities, the creditworthiness of the servicing agent for the pool, the originator of the loans or receivables, or the entities that provide any supporting letters of credit, surety bonds, or other credit enhancements.    PREPAYMENT RISK In a declining interest rate environment, prepayment of loans and other fixed income instruments with high stated interest rates may increase. In such circumstances, the fund may have to reinvest the prepayment proceeds at lower yields. SENIOR LOANS RISKS Senior Loans are subject to the risk that a court could subordinate a Senior Loan, which typically holds the most senior position in the issuer's capital structure, to presently existing or future indebtedness or take other action detrimental to the holders of Senior Loans. Senior Loans are also subject to heightened prepayment risk, as they usually have mandatory and optional prepayment provisions. Senior Loans are subject to the risk that the value of the collateral, if any, securing a loan may decline, be insufficient to meet the obligations of the borrower, or be difficult to liquidate. SHORT POSITION RISK The fund may enter into a short position through a futures contract or swap agreement. Taking short positions involves leverage of the fund's assets and presents various risks. If the price of the asset, instrument or market on which the fund has taken a short position increases, then the fund will incur a loss equal to the increase in price from the time that the short position was entered into plus any premiums and interest paid to a third party. Therefore, taking short positions involves the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. The fund's loss on a short sale could theoretically be unlimited in a case where the fund is unable, for whatever reason, to close out its short position. VALUATION RISK The lack of an active trading market may make it difficult to obtain an accurate price for an instrument held by the fund. Many derivative instruments are not actively traded.
Risk Lose Money [Text]	rr_RiskLoseMoney	Simply defined, risk is the possibility that you will lose money or not make money.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	PERFORMANCE SUMMARY
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Because the fund is new, no performance information is available as of the date of this Prospectus. The fund makes updated performance information available at the fund's website (www.credit-suisse.com/us/funds) or by calling Credit Suisse Funds at 877-870-2874.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Because the fund is new, no performance information is available as of the date of this Prospectus.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	877-870-2874
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.credit-suisse.com/us/funds
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class A
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.75%
Maximum deferred sales charge (load) (as a percentage of the lesser of original purchase price or redemption proceeds, as applicable)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none	[1]
Maximum sales charge (load) on reinvested distributions (as a percentage of offering price)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption or exchange fees (as a percentage of net asset value on date of redemption or exchange) (for shares redeemed or exchanged within 30 days from the date of purchase)	rr_RedemptionFeeOverRedemption	(2.00%)
Management fee	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fee	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	1.16%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	2.16%
Less: amount of fee limitations/expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.92%)	[3]
Total annual fund operating expenses after fee limitations/expense reimbursements	rr_NetExpensesOverAssets	1.24%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	595
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	1,034
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	595
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	1,034
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class C
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a percentage of the lesser of original purchase price or redemption proceeds, as applicable)	rr_MaximumDeferredSalesChargeOverOfferingPrice	1.00%	[4]
Maximum sales charge (load) on reinvested distributions (as a percentage of offering price)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption or exchange fees (as a percentage of net asset value on date of redemption or exchange) (for shares redeemed or exchanged within 30 days from the date of purchase)	rr_RedemptionFeeOverRedemption	(2.00%)
Management fee	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fee	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	1.16%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	2.91%
Less: amount of fee limitations/expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.92%)	[3]
Total annual fund operating expenses after fee limitations/expense reimbursements	rr_NetExpensesOverAssets	1.99%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	302
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	814
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	202
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	814
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class I
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a percentage of the lesser of original purchase price or redemption proceeds, as applicable)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Maximum sales charge (load) on reinvested distributions (as a percentage of offering price)	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption or exchange fees (as a percentage of net asset value on date of redemption or exchange) (for shares redeemed or exchanged within 30 days from the date of purchase)	rr_RedemptionFeeOverRedemption	(2.00%)
Management fee	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fee	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	1.16%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.91%
Less: amount of fee limitations/expense reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.92%)	[3]
Total annual fund operating expenses after fee limitations/expense reimbursements	rr_NetExpensesOverAssets	0.99%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	101
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	511
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	101
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	511

[1] Purchases of shares of $1,000,000 or more may be subject to a 0.50% deferred sales charge on redemptions within 12 months of purchase.

[2] "Other expenses" have been estimated for the fund's first year of operations.

[3] Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.24% of the fund's average daily net assets for Class A shares, 1.99% of the fund's average daily net assets for Class C shares and 0.99% of the fund's average daily net assets for Class I shares at least through the fund's first year of operations (the fund has not yet begun operations). The Trust is authorized to reimburse Credit Suisse for management fees previously limited and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursements must be paid at a date not more than three years after the end of the fund's first year of operations and the reimbursements do not cause a class to exceed the applicable expense limitation in the contract at the time the fees were limited or expenses are paid. This contract may not be terminated before the end of the fund's first year of operations.

[4] 1% during the first year.

XML

Label	Element	Value
Risk Return [Abstract]	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Sep. 18, 2012
Registrant Name	dei_EntityRegistrantName	CREDIT SUISSE OPPORTUNITY FUNDS
Central Index Key	dei_EntityCentralIndexKey	0000946110
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Sep. 12, 2012
Document Effective Date	dei_DocumentEffectiveDate	Sep. 18, 2012
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class A
Risk Return [Abstract]	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	CSOAX
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class C
Risk Return [Abstract]	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	CSOCX
Credit Suisse Strategic Income Fund (Prospectus Summary) | Credit Suisse Strategic Income Fund | Class I
Risk Return [Abstract]	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	CSOIX