Gregory Peck and co-star Charlton Heston both played the infamous Nazi war criminal Dr. Josef Mengele: Peck in The Boys from Brazil, Heston in My Father, Rua Alguem 5555.
Gregory Peck and director William Wyler clashed repeatedly during filming. After Peck stormed off the set one day following a blazing row Wyler told the press, "I wouldn't direct Peck again for a million dollars and you can quote me on that.".
Alfonso Bedoya's last film. A longtime alcoholic, he died before it was released.
Charlton Heston initially turned down the role of ranch foreman Steve Leech because he didn't think the part was big enough. His agent convinced him that it would be worth it just for the opportunity to work with Gregory Peck and William Wyler.
According to Gregory Peck, director William Wyler intended the film to be a left-wing allegory for the Cold War.
Aged 47 at the time of filming, Burl Ives was only 11 years older than Chuck Connors, who played his son.
The character played by Charles Bickford was supposed to represent then US President Dwight D. Eisenhower.
The film is credited with starting the trend for pacifist westerns.