The Swedish Court of Appeals acquitted Nilsson of serious financial crimes and obstruction of an official enquiry. The charges related to payments made to six foreign players.
Nilsson had been convicted of the crimes in the district court and sentenced to a one year in prison.
The appeals court decided that payment to the six foreigners can be regarded as salary, and that Nilsson did not have a hand in the filing of incorrect information.
Former club directors Sune Moberg and Gunnar Svensson have also been acquitted.