Simon Lindberg, 23, leader of the National Socialist Front (NSF) in Skåne was convicted of being an accessory to assault. A 28-year-old friend of Lindberg's was given a six month sentence for offences including assault.
Prosecutor Christofer Ramkvist had earlier told the court in Kristianstad that the incident was a "typical hate crime," and that the people in the RFSL building had been attacked because of their sexual orientation.
Simon Lindberg was convicted of being an accessory to assault, being an accessory to threatening behaviour and vandalism. His friend was convicted of assault, threatening behaviour and careless driving.
Lindberg told news agency TT that the verdict was "political".
"The lay judges were swayed by who I am, and have not judged professionally. There is no evidence, and in such cases we have a principle of justice which says that one should acquit, not convict."
He added that it was "horrible" to be sent to jail, but had no comment as to whether he would accept a lighter sentence.
The incident happened on 20th May last year, when members of RFSL and their friends had gathered at the organization's headquarters to watch the Eurovision Song Contest on television. Lindberg and his friend came to the building, both of them drunk. An initial verbal argument quickly became physical. Several RFSL members say they were attacked with knuckledusters and threatened with knives.
Both Lindberg and his friend admit being at the scene, but Lindberg says he went there to discuss politics. The pair say that they were attacked and had to flee. Lindberg was himself attacked in the argument, cutting his hand on a broken pane of glass.