The film was shot in Sweden, Denmark and Iceland. Filming locations included Stockholm for studio interiors and the openings sequence, while Skåne County in Sweden and Århus in Jutland represented Nangijala, while Þingvellir and Dimmuborgir in Iceland represented the lands of Tengil.
Upon release, unique for adaptations of Lindgren's work, it was given an 11 certificate by the Swedish board of censors, causing the Riksdag to enact an age limit of 7 and above for future films. The film nevertheless maintained the age limit of 11 and above for years until a 7 limit, called "Lex Lejonhjärta", was deemed acceptable.
The source work is widely considered, although the violent content is much toned down on screen, the most political and violent of Lindgren's books, involving themes of dictatorship, occupation, treason, democide, war, suicide and forced labour of nigh-Holocaustian reminiscence. Most of the named characters do not survive the film (although its setting in concurrent realities soften this fact). In a cruel quirk of fate, actor drowned in a diving accident less than three months before its release, a fate shared with his character in the film and book.