For the African scenes, Reginald Denny invented the first radio-controlled model airplane and, with Osmond Borradaile, put a camera on board in 1946.
Later in life, Gregory Peck lamented that he felt this film was overlooked because it was released in between two of his more well-known films: Duel au soleil (1946) and Le mur invisible (1947). Despite this film's critical success, Peck felt that it quickly became forgotten.
According to Gregory Peck biographer, Michael Freedland, director Zoltan Korda and producer Benedict Bogeaus were intensely antagonistic with one another. In his book, "Gregory Peck: A Biography," Freedland recounted a story Peck described from the production of this film. In Peck's recollection, Bogeaus arrived on set late one day while Korda was deep in concentration setting up a shot. Bogeaus loudly announced that he had come up with the perfect title for the picture, "Congo". Bogeaus's brusqueness interrupted Korda's concentration, and the director launched into a profanity-laced tirade. Peck then recalled that Korda pulled a pocketknife out of his pocket, brandished it against Bogeaus's chest, and exclaimed, "You get off my set and if you ever come back here again I'll cut your liver out." According to Peck, Bogeaus was not seen on set again.
Gregory Peck helped Zoltan Korda land his position as director of the film. Peck recommended Korda to the studio because he had the reputation for creating successful films with exotic locales and intense action sequences.