Trade paper Variety erroneously reported in its review that this Metro-Goldwyn-Mayer movie was shot in Africa. The exteriors were lensed in Jamaica in the Caribbean as it could not be shot in Africa due to political unrest. Ironically, around the same, another picture from MGM, Graham Greene's The Comedians (1967), was set in the Caribbean, but filmed in Benin, West Africa.
Jim Brown scheduled an interview in 1968 with critic Roger Ebert to promote this movie but canceled it at the last minute. He apologized later and told Ebert he couldn't do it because he just didn't like the movie. He said, "It's the only film I've done I really didn't like. If I'd come here to Chicago and some guy had said, I don't like your flick at all, how could I disagree with him? If you put yourself on the line, you have to be able to believe what you say. But if you KNOW the movie's no good, man, and you have to say it is, that eats you up. When I read the script, I thought it was going to be a political movie, and I thought we might even have a hassle. But the director simplified it to brutality and bad taste."
This movie re-unites Rod Taylor with Yvette Mimieux eight years after they co-starred in The Time Machine (1960).
The film was a particular influence on Quentin Tarantino who used several tracks from the score for his film Inglourious Basterds (2009). Rod Taylor appears in that movie as Winston Churchill.
The 37-year-old Rod Taylor began to focus on action movies with this film, turning down all offers for more dramatic work.