He made his debut in Italian Serie A in October 1972 with Fiorentina, whom he later captained, also eventually inheriting the number 10 shirt. He won the Coppa Italia (Italian Cup) during the 1974–75 season, as well as the 1975 Anglo-Italian League Cup that season, over West Ham. He narrowly missed out on the Serie A title with Fiorentina during the 1981–82 season, losing out to rivals Juventus by a single point on the final match-day. Antognoni played 412 games with Fiorentina and scored 61 goals. Antognoni is regarded as a Fiorentina legend, and as one of the club's best ever players, as he played for the club throughout his entire Italian professional career between the 70s and 80s. He holds the record for the most appearances in Serie A for Fiorentina, with 341 appearances.