Although the movie title refers to three coins only two coins are actually thrown into the fountain.

Average Shot Length (ASL) = 16 seconds (including opening Sinatra travelogue montage).

Served as basis for unsold TV pilot starring Cynthia Pepper, Yvonne Craig and Joanna Moore.

The first motion picture filmed in CinemaScope outside of the United States. Prior to beginning principal shooting, 20th Century-Fox studio execs warned producer Sol C. Siegel and director Jean Negulesco that they would have a difficult time with the new film format away from the controlled settings of the studio. Siegel and Negulesco solved this dilemma by simply taking the studio's entire technical crew along to Rome.

We only see two coins thrown in the fountain, but we told of a third thrown in by Georgio.