On the local level, Aasland held various positions in Skien municipality council from 1991 to 2003. He chaired the local party chapter from 1995 to 2000, and was the deputy leader of the county chapter from 1998 to 2000. During the same period he was a member of the Labour Party national board.
Aasland is an educated electrician. He spent parts of his professional career in trade unions.