The interior scenes inside of the hunting lodge were all filmed on a soundstage at Pinewood Studios in England on a life-sized set.
The screenplay was adapted by author David D. Osborn from his own novel of the same name. The movie credits refer to a work called "The All-Americans" but in actuality the book was simply called "Open Season" (Dial Press, New York, 1974).
Veteran Spanish actor Simón Andreu is credited with the role of "Barman" in the cast listing during the credits of all three of the English-language versions, but his performance not actually present in any of those prints in the versions which have turned up on home video.
The movie was filmed in four countries: Spain, Italy, England and the USA.
The film was first released the same year as its source novel of the same name by David D. Osborn was first published in 1974.