Maldera was born in Milan, and he spent a large part of his career with one of the major local clubs of his city A.C. Milan (1971–1982); with the club, he won a Serie A title in 1979, two Coppa Italia trophies in 1972 and 1977, a Serie B title (earning promotion to Serie A the following season, following Milan's involvement in the 1980 Totonero football betting scandal) in 1981, and a Mitropa Cup, during his final season with the club, in 1982, also serving as the club's captain. Throughout his career, he also played for Bologna F.C. 1909 (for a half season loan, as a youth, during his time with Milan), local rivals Internazionale, A.S. Roma and A.C.F. Fiorentina.