at the 1990s constanze jahn was one of the leading female chess players in east germany. in 1991, in graz she shared first place with tatjana lematschko in women's world chess championship zonal tournament and won the right to take part in an interzonal tournament. in 1991, constanze jahn participated in women's world chess championship interzonal tournament in subotica where ranked 28th place. constanze jahn twice won german women's fast chess championships: in 1998 and in 2005. in 2001, she won the bronze medal in this tournament. in 1991, she was second in the german women's blitz chess championship.