He was also the father of Teddy Diaz, the founding guitarist of the Filipino Rock band The Dawn.
Diaz's first part in front of the camera was an uncredited role as a Japanese General in American Guerrilla in the Philippines (1950) directed by Fritz Lang.
He appeared in The Big Bird Cage, Black Mama White Mama and played Satan in Eddie Romero's Beast of the Yellow Night.
He appeared in a number of other Filipino horror films in the 70s such as Blood Thirst, Beyond Atlantis, Daughters of Satan and Night of the Cobra Woman.
His remains were shared with his son at Santuario de San Antonio Parish in Makati City.