He achieved recognition for his performance as mobster Virgil Sollozzo in the crime film The Godfather (1972) and appeared in several other productions alongside Hollywood's biggest screen stars.

[2] Lettieri — credited as "Anthony Lettier" — had a role in the 1958 Perry Mason episode "The Case of the Fugitive Nurse" as Arthur Strome.

[4] Before his notable film roles materialized, Lettieri offered his services as a dialogue coach on five productions, including the 1968 wartime classic Where Eagles Dare.

In his 2024 autobiography, Al Pacino describes how Lettieri took him to visit a suburban New York family that resembled the Corleones after telling him, “You should meet this guy.

[citation needed] He wrote the film adaptation that became the screenplay for the 1971 gangster movie Villain, which starred Richard Burton and Ian McShane.