Massi entered the cinema industry in 1952 as assistant camera operator, and in 1954 he became a cameraman. Ten years later he began to work as cinematographer, and in 1973 he debuted as film director with Macrò. He obtained a great commercial success with the Mark il poliziotto film series, then with a series of poliziotteschi starred by Maurizio Merli.
Massi also worked on television, directing the 1987 TV series Due assi per un turbo. His son Danilo is also a film director.