The Swiss National Bank (SNB) made a profit of SFr6.9 billion ($6.8 billion) in the first nine months of 2009, it announced on Friday.
The central bank attributed its surplus to valuation gains in gold and foreign currencies, as well as the recovery of markets around the world.
It called the result "extremely favourable". Last year the SNB lost SFr4.7 billion.
The bank's foreign currency trades netted it SFr3.1 billion as against a loss of SFr2.4 billion in 2008.
On Thursday, SNB board member Thomas Jordan said the bank would focus on normalising monetary policy in the medium term and guarantee price stability in the long term.
swissinfo.ch and agencies