Decker grew up in light pine. In 1967 Decker a call to Heinz cross- Man in Christmas broadcast Between breakfast and roast goose, where tall children were asked to report to the rudder section in Leipzig. As early as 1970 won Decker at the Spartakiade and at the Youth World Championships. 1973 Decker was with the GDR eight European champions. In 1974, he joined the coxless four. In the occupation Siegfried Brietzke, Andreas Decker, Stefan Semmler and Wolfgang skimmed the boat from SC DHfK Leipzig dominated over the next few years, this class of boat. 1974 in Lucerne and 1975 in Nottingham, the four rowers were world champions, 1976 Montreal Olympic champion. 1977 in Amsterdam and 1979 in Bled, the boat was world champion again, only in 1978 in New Zealand succumbed to the Soviet boat and won silver. In the Olympic season 1980 skimmed injured his hand and was represented by Jürgen Thiele. Together, the crew won at the Olympic Games in Moscow well before the boat of the hosts.
After the turn Decker was until 1998 chairman of the Saxon State Sports Association. He was elected for the fifth vice president of the German Sports Federation in 1992, stepped down from that position but after two years due to illness back.
For his long-standing commitment to sport him in 2012 the Saxon Order of Merit was awarded.