Production notes

Trumbo wrote the first version of the script in 1964, in collaboration with Luis Buñuel, who was to direct. However, financing for this project failed to materialize, and it was abandoned. In 1966, producer Bruce Campbell (Hey, Hey, Hey, It's Fat Albert, The Picasso Summer) teamed up with Trumbo, who wrote a film script and was attached to direct. This project was initially set up at Warner Bros., but those plans fell through, so Campbell and Trumbo invested $80,000 and attracted 25 investors to invest $600,000. The total cash outlay for the film was $750,000, but deferred technical fees put the budget over $1 million. The film distinguishes between Joe's reality and fantasy by presenting the scenes in the hospital in black-and-white, and his dreams and memories in color. His dreams, such as when he talks to his dead father and Jesus Christ, are drug-induced, and the color is more saturated than it is during his memories, such as the fishing trip and his last night with Kareen. Joe's injuries are never seen in film, as his face is always covered by a mask and his body is always covered by the hospital sheets.

The film has received mixed reviews. Roger Ebert gave it a full four-stars out of four, writing that Trumbo had handled the material, "strange to say, in a way that's not so much anti-war as pro-life. Perhaps that's why I admire it. Instead of belaboring ironic points about the 'war to end war,' Trumbo remains stubbornly on the human level. He lets his ideology grow out of his characters, instead of imposing it from above." Roger Greenspun of The New York Times, however, stated that much of the film was "a mess of clichéd, imprecise sentimentalizing and fantasizing. On any terms that I might recognize and possibly credit, Johnny Got His Gun is a stultifyingly bad movie." Gene Siskel of the Chicago Tribune gave the film two-and-a-half stars out of four. He reported that he watched it twice, and, while he found it to be "as savagely effective as any antiwar film" after the first viewing, he changed his opinion after the second, feeling that "it didn't work at all," with the color flashback scenes "poorly acted and scripted", and the dreams "frequently much too detailed and barely illusory. In the black-and-white sequences, Trumbo is much more disciplined and effective." Charles Champlin of the Los Angeles Times wrote that the film "seems too late—a passionate anti-war sermon arriving at a time when the sermon has been done often and better, and more to the point has long since been accepted by the congregation. Paradoxically, the particular horror which Trumbo lays before us is at once so special and terrible and so manifestly symbolic, that by the end it has lost much of its power to move us. You admire the passion but cannot be sure what it achieved." Similarly, Tom Shales of The Washington Post said that the film "means well," but "Trumbo is not nearly sophisticated enough as a writer, nor proficient enough as a director, to either grip or alarm us for very long [...] Trumbo can't decide whether to fill his movie with symbols or people, so the screenplay is usually hollow and vague and never quite true." Tom Milne of The Monthly Film Bulletin thought the film "might have worked" if Trumbo had "treated the whole film in the black-and-white, expressionist manner of the hospital scenes," but, as it is, the flashback and fantasy sequences "not only reveal influences as varied and ill-advised as Fellini and M*A*S*H, but provide Joe with a very mundane and rather lachrymose biography; the Unknown Soldier is no longer an awesome symbol when he is provided with a name, rank and serial number." On the review aggregator website Rotten Tomatoes, 67% of 21 critics' reviews of the film are positive, with an average rating of 6.7/10.

The Japanese filmmaker Akira Kurosawa cited Johnny Got His Gun as one of his favorite films. A TV film of the same name was made in Czechoslovakia in 1984. The 1988 song "One" by heavy metal band Metallica has a central character similar to the one in Johnny Got His Gun, and the music video released in early 1989 features a number of clips from the film. In 2008, actor Benjamin McKenzie performed as Joe Bonham in a "live on stage, on film" staging of Bradley Rand Smith's 1982 off-Broadway play based on Trumbo's novel. After a "city-by-city, single-screen release" of the filmed performance, a special educational DVD became available free of charge to every high school library in the U.S. in October 2010. The DVD contains the 2008 film, a pre-screening and post-screening discussion guide for students, a 15-minute featurette on the making of the 2008 film, a history of the novel, and the 1971 film's theatrical trailer.