Defence Minister Samuel Schmid has had his gall bladder removed. Doctors in Bern said on Friday there were no complications.
Schmid, who was admitted to hospital on Wednesday, is expected to be released on Sunday and resume his duties by the middle of next week.
His hospital stay comes only weeks after Finance Minister Hans-Rudolf Merz underwent a quintuple bypass operation. Merz returned to work on Monday.
Schmid has been under considerable pressure during the past few months over his handling of army affairs. His appointee as head of the armed forces was forced to resign in August after being implicated in a case of sexual harassment.
He has also been criticised over two fatal accidents. In July 2007 six recruits died in an avalanche on the Jungfrau, and in June 2008 five drowned in a rafting accident.
Despite the pressure, Schmid has resisted calls to step down.