Mitropoulos started his football career at his local club,
Aris Petroupolis. In 1976, he joined
Ethnikos Piraeus, where he played five seasons and his performances attracted the major Greek clubs. In 1981, Mitropoulos moved to
Olympiacos. He was used both as a striker and an attacking midfielder. Mitropoulos was distinguished for his strength, aggression, passion and his aerial ability, while he was also a technichal player. There he played for 11 seasons, becoming one of the team's main players and won three
Championships, two
Cups and a
Super Cup. On 16 July 1992 Mitropoulos left Olympiacos and signed for their rivals,
AEK Athens. There he was established in the squad, with the manager,
Dušan Bajević, using him mainly as a super-sub, due to his advance age. He spent two seasons at the yellow-blacks, winning as many league titles. On 22 July 1994, after his contract at AEK had expired he joined
Panathinaikos, albeit only one game. He also played for
Apollon Athens,
Iraklis and before returning to Olympiacos in 1997 to finish his career at the age of 40. ==International career==