Campbell started all 10 games of the 2006 season for the Berlin Thunder and led the team in passing with 1,264 yards, completing 116 of 204 attempts with 10 touchdowns and 4 interceptions. His totals in attempts and completions led the league. The Thunder compiled a 2-7-1 record in 2006, finishing sixth in the six-team league. The tie, a 17-17 draw on the road against the Hamburg Sea Devils on April 1, 2006, was one of only two ties to occur in the now-defunct NFL Europe (the league played its final season in 2007 under the moniker NFL Europa).