[2] His uncle is filmmaker Romolo Guerrieri and his brother was actor Ennio Girolami.

[2] Among his early credits included uncredited roles in directing films such as Few Dollars for Django (1966) and A Ghentar si muore facile (1967).

[2] After releasing the Western Kill Them All and Come Back Alone (1968), Castellari did a Macaroni war film titled Eagles Over London.

[2] By the early 1970s, Castellari began exploring other genres as well such as the thriller Cold Eyes of Fear (1971), the comedy Hector the Mighty (1972), and the comedic swashbuckler The Loves and Times of Scaramouche (1976).

[2] He directed his first poliziotteschi film with High Crime starring Franco Nero.