A studio production chart in the 24 August 1929 Exhibitors Herald-World cited a 7 May 1929 starting date for Trader Horn.
       The following onscreen acknowledgment appears in the film's titles: "M-G-M acknowledges Governors and governmental officials of the Territory of Tanganyika, the Protectorate of Uganda, the Colony of Kenya, the Anglo-Egyptian Sudan, [and] the Belgian Congo, whose courtesy and cooperation made this picture possible...and the director offers his thanks for the courageous and efficient services of the White Hunters, Maj. W. V. D. Dickinson, A. S. Waller, Esq., J. H. Barnes, Esq., [and] H. R. Stanton, Esq., who were chiefly responsible for the expedition's ability to traverse 14,000 miles of African velt and jungle." According to a FD news item, following its publication, Trader Horn became one of the best-selling books of its time. The film was the first non-documentary film to be shot almost entirely on location in Africa. A Jan 1930 AC article notes that the film was nearly half completed when the studio informed the crew in Africa that Hollywood was sending a sound crew to meet them. They were told that "the world was demanding its pictures all-talking." According to an Apr 1931 Photo article, M-G-M secretly sent a second unit to Tecate, Mexico, away from American laws that secured the ethical treatment of animals, to film scenes of animals fighting with each other, which they were unable to capture on film in Africa. In Mexico, lions were reportedly starved for several days in order to ensure immediate and particularly vicious attacks on hyenas, monkeys and deer.
       Modern sources relate the following information about the film: Tim McCoy was originally chosen to play the title role; Thelma Todd was tested for the part of "Nina" and M-G-M production head Irving Thalberg reportedly considered Jeanette MacDonald for the part. During the filming of a scene in which white hunter Major W. V. D. Dickinson and director W. S. Van Dyke doubled for the leading men, a charging rhino nearly killed Dickinson, who incorrectly thought that the director was in distress and jumped into the rhino's path to protect him. During production, Van Dyke and many of his crew contracted malaria and were treated with quinine. Despite the British authorities' insistence that no one travel to the Murchison Falls, a known sleeping-sickness area, the director took his crew there for filming. The production was marred by at least two fatal disasters. In the first instance, a native crew member fell into a river and was eaten by a crocodile; in the other incident, which was captured on film, a native boy was struck by a charging rhino. Misfortunes of lesser consequence on the African location included flash floods, sunstroke, swarming locusts and tsetse-fly and ant attacks. Despite months of sound filming, almost all of the dialogue sequences in the film were re-shot on M-G-M's Culver City backlot after the troupe returned from Africa because of the poor quality of the location footage. As the script called for speaking scenes involving African natives Mutia Omoolu and Riano Tindama, they were brought back to Hollywood for additional shooting. With all the production activity in Culver City, rumors began circulating in Hollywood that the entire production was filmed on the M-G-M lot and that the African expedition did not take place. For this reason, the studio decided to scrap the backlot footage of Marjorie Rambeau, who had replaced Olive Golden as "Edith Trent." Modern sources add the following credits: Red Golden , Asst dir; Josephine Chippo, Script clerk; John McClain, Press agent and Miss Gordon, Hairdresser. Although modern sources indicate that the film was originally released with a short introduction in which director Cecil B. DeMille discusses the film's authenticity with author Alfred Aloysius Horn, and that the three-minute introduction was deleted from the negative in 1936, when the picture was re-issued, neither the viewed print nor the cutting continuity contain the introduction. The final production cost was pegged at $3,000,000.
       Leading actor Harry Carey was married to actress Olive Golden. According to modern sources, following publicized rumors of an affair between stars Duncan Renaldo and Edwina Booth (formerly Josephine Woodruff) during production, Renaldo's wife, Suzette, filed for divorce and later filed a $50,000 lawsuit against Booth for "alienation of affection." On 17 Jan 1931, Duncan Renaldo was arrested on charges that he entered the United States illegally and was later sentenced to two years in federal prison. After serving less than two years, Renaldo received a pardon from President Franklin Delano Roosevelt in 1936, after which he left the country, re-entered legally and became a U. S. citizen. Booth contracted a rare tropical disease while filming in Africa that affected her nervous system and reportedly forced her to remain confined to a darkened room for the better part of six years.
       Trader Horn was nominated for an Academy Award for Best Picture of the 1930-31 season, and director W. S. Van Dyke was awarded the Red Cross Medal by the Japanese government for his outstanding achievement in direction.
       In 1932 United Artists released a Mickey Mouse animated short, entitled Trader Mickey, which was a spoof of this film. Other take-offs on Trader Horn include an X-rated 1970 film entitled Trader Hornee (see AFI Catalog of Feature Films, 1961-70; F6.5148), and Trader Hound, a 1931 M-G-M "Dogville Comedy" short subject. M-G-M made another version of Trader Horn in 1973 with Reza S. Badiyi directing and Rod Taylor and Anne Heywood starring.