Finnish-born Markku Slawyk won a silver medal with the West German male field hockey team at Los Angeles in 1984, losing the final against Pakistan 2-1 after extra time. He also won the Youth Worlds in 1982, and a bronze medal at the 1983 Europeans. In 1986 he added another bronze at the Worlds, and won the Champions Trophy. He won 96 international caps (including 12 indoor) between 1982-87.
Domestically, Slawyk played with RTHC Bayer Leverkusen and later Uhlenhorster HC Hamburg. After his active career, he turned to coaching and became Regional Chief Coach of Hamburg. In 2007, he became Chief Youth Coach of the German Field Hockey Association. He married his teammate Gaby Uhlenbrock.