In 1979 Valchev joined Akademik Sofia, where he scored 38 goals for two seasons. In 1981 he left to join Levski Sofia, where he won two Bulgarian League titles, two Bulgarian Cups and one Cup of the Soviet Army. Valchev had a successful start to his career at the club by being the league's top goalscorer in its inaugural season, scoring 24 goals. Between 1981 and 1986 he scored 109 goals in 177 matches for the club in all competitions. In 1983, Valchev scored two goals for Levski against one of the biggest German clubs VfB Stuttgart with which Levski eliminated the Bundesliga team.