Mario Caiano was born in Rome, Italy on February 13, 1933. After grade school, he registered in college under the alias Mariano Cajano where he alternated his university studies in philology with his aprenticeship in the film world in working as an assistant director and occasionally a scriptwriter for famous Italian directors such as Sergio Grieco, Fernando Cerchio, Carlo Ludovico Bragalia, Vittorio Sala, Riccardo Freda, Edgar G. Ulmer and Camillo Mastrocinque. In 1962, Caiano made his film debute as a director with Ulisse contro Ercole. From then on, he made films of virtually every genre. He directed the very first Italian western, Il segno del coyote, the interesting gothic horror flick Amanti d'oltretomba which starred Barbara Steele, and the psychological thriller L'occhio nel labrinto, and the captivating detective thriller A tutte le auto della polizia.

Among other things, Caiano wrote the script for Nelle pieghe della carne which was directed by Sergio Bergonzelli. He has recently been very active in Italian TV work with films such as Un'estate, un inverno (1971), Diagnosi (1974) Astuzia per astuzia (1976) and many others to this day.