Johansen played his youth football for amateur club Ryvang FC, before making his senior debut for B 1903 in 1968. With B 1903, he won the 1969 and 1970 Danish football championship. Johansen scored both goals in B 1903's 2-1 win against Celtic FC in the 1971-72 European Cup, though B 1903 was eliminated 4-2 on aggregate. In 1972, Johansen moved abroad to play for Swedish club Helsingborgs IF. He moved back to B 1903 in 1978, but suffered a knee injury, and ended his playing career in 1980.
Johansen started his coaching career with amateur team HGI from 1981 to 1982, and Espergærde IF from 1983 and 1984. In 1988, Johansen was back at B 1903, coaching the youth team. In 1989 he became B 1903 assistant manager. He became manager of B 1903 in 1990, and led the team to the quarter-finals of the 1991-92 UEFA Cup, beating Aberdeen, Bayern Munich, and Trabzonspor, before being eliminated by Torino Calcio. In 1992, Johansen became the first coach of F.C. Copenhagen, a newly created fusion of B 1903 and KB, and guided the team to the 1992 Danish Superliga championship. In 1994, Keld Kristensen was named manager of FC Copenhagen, before Johansen managed the club again from 1994 to 1995.