Some movie posters for this film featured a long text preamble that read: "At 29, Charles Heller was a mathematician without equal. At the CIA, he was a computer expert without peer. But when terrorists murdered the most important woman in his life, he became an assassin without experience. To avenge her death, the CIA trained him, briefed him, armed him, and then...they abandoned him. The first 11 minutes will absolutely shock you. The last 11 minutes will rivet you to your seat. The Amateur".
John Savage was cast in the lead role in this film after the success of his earlier movie The Deer Hunter (1978).
This was the second consecutive espionage movie appearance for actress Marthe Keller whose previous film had been The Formula (1980). It was also the second consecutive spy movie for cinematographer John Coquillon whose previous film had been Final Assignment (1980).