Kelly's Heroes was produced as a U.S.–Yugoslav co-production, with principal photography taking place across what is now Croatia and Serbia on a $4 million budget. The Yugoslav Army supplied extensive World War II–era tanks, vehicles, uniforms, and artillery, allowing the production to stage large-scale battle sequences and recreate the European theater with a degree of realism uncommon for war comedies of the period. The combination of American studio backing and Yugoslav military resources contributed to the film's ambitious scale and visual identity.
Released on June 23, 1970, Kelly's Heroes gained lasting popularity through television broadcasts and home-media releases, becoming known for its off-beat tone, eclectic cast, and mixture of action, satire, and ensemble comedy. In the decades since its release, it has developed a reputation as a unique hybrid of war film and caper movie