Mega buyouts, defined as investments larger than $5 billion, produced returns of 22.4 percent in the 12 months to end June, according to data from Thomson Reuters.
These deals, such as the buyouts of Alliance Boots and Valentino Hugo Boss, have come under the most scrutiny as economic conditions have deteriorated.
Medium-sized deals in the $400 million to $1 billion range narrowly outperformed the mega buyouts, returning 24.7 percent over the same period.
The improvement in returns from European buyouts will provide a ray of hope that mega deals done at the peak of the private equity boom have survived recession and can continue to weather the turbulent markets.
Private equity returns plummeted in the wake of the credit crisis as firms took large hits on companies bought between 2005 and 2008, prompting fears that many could collapse under the weight of their debt.
All buyouts returned 15.3 percent in the 12 months to end June, according to the data, outperforming benchmark European indexes.
The FTSE 100 total return index returned 13 percent over the same period, while the Morgan Stanley Euro Equity total return index returned 12.2 percent.
Private equity returns are likely to come under pressure in the second half as those public market benchmarks, against which buyout firms value their private companies have fallen again.
The FTSE 100 has fallen in value by more than 10 percent since the end of June.
(Reporting by Simon Meads. Editing by Jane Merriman)