Publicity for this picture stated that this movie was the first villainous role of Gregory Peck's career. Peck felt that his portrayal of Nazi war criminal Dr. Josef Mengele was the only completely unsympathetic role he ever performed.
For his role as a notorious Nazi, actor Gregory Peck had his famous "widow's peak" hairline shaved off, his eyebrows cropped, put on a little Hitler mustache and then had added white face paint make-up. Publicity for the picture stated that Peck bore an uncanny resemblance to photographs of the real Josef Mengele which had at the time been recently smuggled out of South America.
Austria's The Kölnbrein Dam doubled for the Swedish dam where an assassination sequences occurs. The dam was under construction at the time of principal photography and was then not as yet a functioning dam.
Director Franklin J. Schaffner previously directed the World War II movie Patton which won several Academy Awards including the Oscar for Best Picture. The Boys from Brazil was the only other picture related to the Second World War that Schaffner directed.
The film was nominated for three Academy Awards at the 1979 Oscars but failed to win any statuettes. Ironically, it was Laurence Olivier playing the Nazi hunter and not Gregory Peck in the meatier lead role who was nominated for Best Actor.
James Mason reportedly was not interested in the script for "The Boys from Brazil", until he found out that his friends "Greg" and "Larry" were already signed-up. "Greg", of course, was Gregory Peck, and "Larry" was Sir Laurence Olivier.