Production notes

Production on Cannibal Holocaust began in 1979, when director Ruggero Deodato was contacted by West German film distributors to make a film similar to his previous work, Last Cannibal World. He accepted the project and immediately set out to find a producer, choosing his friend Francesco Palaggi. The two first flew to Colombia to scout filming locations. Leticia was chosen as the principal filming location after Deodato met a Colombian documentary filmmaker at the airport in Bogotá, who suggested the town as a location ideal for filming. Other locations had been considered, specifically those where Gillo Pontecorvo's Burn! had been shot, but Deodato rejected these locations because of a lack of suitable rainforest. Deodato conceived the film's premise while talking to his son about news coverage of the Red Brigades' terrorism. Deodato thought the media focused on portraying violence with little regard for journalistic integrity and believed journalists staged certain news angles to obtain more sensational footage. The Italian media was symbolized by the behavior in the film team in Cannibal Holocaust, the depiction of whom was also influenced by the works of Gualtiero Jacopetti, a documentary filmmaker of whom Deodato was a fan. Jacopetti and his partner, Franco Prosperi, are credited with popularizing Mondo films, a genre of documentary, with their first release, Mondo cane. Mondo films focused on sensational and graphic content from around the world, including local customs, violence, sexuality, and death. Deodato included similar content in Cannibal Holocaust, such as graphic violence and animal death, and the documentary that is produced in Cannibal Holocaust resembles a Mondo film. The scene of Monroe bathing naked in a river and the scene of a forced abortion rite have also been noted as being similar to scenes in Antonio Climati's Mondo film Savana violenta. The Italian screenwriter Gianfranco Clerici wrote the script under the working title I figli della luna (The Sons of the Moon). He had collaborated with Deodato in his previous films Ultimo mondo cannibale and The House on the Edge of the Park, the latter of which was filmed before Cannibal Holocaust but released afterward. The screenplay included multiple scenes that did not make the film's final cut, including one in which a group of Ya̧nomamö cuts off the leg of a Shamatari warrior and feeds it to piranhas in a river. This scene was to take place directly after Monroe's team rescues a smaller group of Ya̧nomamö from the Shamatari. Attempts were made to film this scene, but the underwater camera did not operate properly, and the piranha were difficult to control. As a result, Deodato abandoned his efforts, and still photographs taken during the scene's setup are its only known depiction. The originally scripted version of The Last Road to Hell, which was written to depict soldiers advancing upon an enemy position, also went unused, as Deodato instead decided to use stock footage of political executions for the segment in order to draw further parallels to the films of Jacopetti. The character names Mark Williams and Shanda Tommaso in Clerici's screenplay were also changed to Mark Tomaso and Faye Daniels, respectively, in the film.

Deodato decided to film Cannibal Holocaust in English to appeal to a wider audience and lend the film credibility. There is one scene in Spanish, about seven minutes in, for which the subtitles vary in different versions of the film. However, the film had to establish a European nationality so that it could be more easily distributed among European countries. Under Italian law, for the film to be recognized as Italian, at least two actors who spoke Italian as a native language had to star in the film. Luca Giorgio Barbareschi and Francesca Ciardi, two inexperienced students from the Actors Studio in NYC, were cast as Mark Tomaso and Faye Daniels, respectively, in part because they were native Italian speakers who also spoke English. Deodato also hired an American from the Actors Studio, Perry Pirkkanen, to play Jack Anders. A friend of Pirkkanen was initially cast to play Alan Yates, but he dropped out of the film shortly before the production team left for the Amazon. He instead appears in the film as an ex-colleague of Yates. Casting director Bill Williams subsequently contacted Carl Gabriel Yorke to play the role. Yorke, a stage actor who had studied under Uta Hagen, was chosen in part because he was the right size for the costumes and boots, which had already been purchased. Because Cannibal Holocaust was a non-union production, Yorke originally wanted to be credited under the stage name Christopher Savage, although he ultimately decided it to be unnecessary because of the film's obscurity and remote filming location. Robert Kerman had years of experience working in adult films under the pseudonym R. Bolla, including the well-known Debbie Does Dallas, before breaking into the Italian film industry. Kerman was recommended to Deodato for his previous film, The Concorde Affair, in which Kerman played an air traffic controller, and his performance impressed Deodato enough to have Kerman cast as Harold Monroe in Cannibal Holocaust. Kerman went on to star in the Italian cannibal films Eaten Alive! and Cannibal Ferox, both directed by Umberto Lenzi. Kerman's then-girlfriend Kate Weiman was cast as one of the station executives, as she was available to film in both New York City and Rome.

Film historian David Kerekes contends that the film's sense of reality is based on the direction and the treatment of the film team's recovered footage, noting that the "shaky hand-held camerawork commands a certain realism, and 'The Green Inferno,' the ill-fated team's film-within-a-film here, is no exception", and that "this very instability gives the 'Green Inferno' film its authentic quality." David Carter of the cult horror webzine Savage Cinema says that Deodato's methods added a first-person narration quality to the film team's footage, writing: "The viewer feels as if they are there with the crew, experiencing the horrors with them." Deodato was proud of other aspects of the cinematography, namely the numerous moving shots using a standard, shoulder-mounted camera, forgoing the use of a steadicam. Kerekes noted the animal slaughter and inclusion of footage from The Last Road to Hell as adding to the sense of reality of the film. Lloyd Kaufman of Troma Entertainment compares these scenes to Vsevolod Pudovkin's theory of montage, saying: "In Cannibal Holocaust, we see the actors kill and rip apart a giant sea turtle and other animals. [...] The brain has been conditioned to accept that which it's now seeing as real. This mixture of real and staged violence, combined with the handheld camerawork and the rough, unedited quality of the second half of the movie, is certainly enough to convince someone that what they are watching is real." Deodato says he included the execution footage in The Last Road to Hell to draw further similarities to Cannibal Holocaust and the Mondo filmmaking of Gualtiero Jacopetti.

Principal photography began on 4 June 1979. The scenes featuring the film team were shot first with handheld 16mm cameras in a cinéma vérité style that mimicked an observational documentary, a technique Deodato had learned from his mentor Roberto Rossellini. This same style was also used by Climati in his Mondo film Ultime grida dalla savana, which may have been influential on Deodato's direction. After shooting with the film team was completed, Kerman flew down to film his scenes in the rainforest and then to NYC to film exterior shots in the city. Leticia was only accessible by aircraft, and from there, the cast and crew had to travel by boat to reach the set. The interior shots of NYC were filmed later in a studio in Rome. Production on the film was repeatedly delayed while in the Amazon. After the actor originally cast as Alan Yates dropped out of the role, filming was halted for two weeks until new casting calls were completed and Yorke arrived in Leticia. During principal filming with Kerman, the father of the actor who played Miguel was murdered, and production was again halted as the actor flew back to Bogotá to attend his father's funeral. The locale also presented problems for the production, in particular the heat and sudden rainstorms, which sporadically delayed filming. Interpersonal relationships were strained on the set. Kerman and Deodato frequently clashed, as the two got into long, drawn-out arguments every day of shooting, usually because of remarks Deodato made that Kerman took offense at. Although Deodato noted that the two were always friendly again a few minutes later, Kerman expressed his personal dislike of Deodato in several interviews. He described Deodato as remorseless and uncaring on set and stated that he did not believe that Deodato had a soul. Kerman also noted hostile treatment of other cast and crew members by Deodato, stating: "He was a sadist. He was particularly sadistic to people that couldn't answer back, people that were Colombian, [and] people that were Italian but could be sent home." Yorke and co-star Perry Pirkkanen also did not get along, which Yorke attributed to disappointment that Pirkkanen felt after his friend dropped out of the production. Yorke also alienated Ciardi after he declined to have sex with her in preparation for filming their sex scene. Multiple cast and crew members were uncomfortable with the film's graphic content, in particular, the genuine killing of animals. Yorke described the shoot as having "a level of cruelty unknown to me" and was initially unsure if he was taking part in a snuff film. When his character was scripted to kill a pig on camera, Yorke refused, leaving the duty to Luca Barbareschi. Yorke had traveled with the pig to the set and felt he had formed a relationship with the animal. When it was shot, the emotional impact of the pig squealing caused Yorke to botch a long monologue, and retakes were not an option because the production lacked access to additional pigs. Kerman similarly objected to the killing of the coati and stormed off the set while its death scene was filmed; he had repeatedly pressed Deodato to let the animal go in the minutes leading up to filming. Pirkkanen cried after filming the butchering of a turtle, and crew members vomited off camera when a squirrel monkey was killed for the film. The film's sexual content also proved a point of contention among the cast members. Ciardi did not want to bare her breasts during the sex scene between her and Yorke, and she became agitated with him during the filming of the scene. When she refused to comply with the direction, Deodato led her off the set and screamed at her in Italian until she agreed to perform the scene as instructed. Yorke also became severely upset while filming a scene in which his character takes part in the rape of a native girl. The film's content had given Yorke anxiety throughout his time in Colombia, and this tension peaked during the rape scene. His experiences on set ultimately weighed so heavily on him that Yorke ended his relationship with his girlfriend in NYC shortly after his return from the Amazon. Yorke experienced unfair payment practices when his first payment for the film arrived in Colombian pesos and was less than agreed upon. He refused to continue shooting until he was paid the correct amount in United States dollars. The native extras also went unpaid for their work despite their involvement in numerous dangerous scenes, including one in which they were forced to remain inside a burning hut for an extended period.

Cannibal Holocaust was innovative in its plot structure, specifically with the concept of the "found footage" being brought back to civilization and later viewed to determine the fate of the crew that shot it. This was later popularized as a distinct style in Hollywood cinema by The Last Broadcast and The Blair Witch Project, both of which use similar storytelling devices. Each film uses the idea of a lost film team making a documentary in the wilderness, and their footage returned. Advertisements for The Blair Witch Project also promoted the idea that the footage is genuine. Deodato has acknowledged the similarities between his film and The Blair Witch Project, and though he holds no malice against the producers, he is frustrated at the publicity that The Blair Witch Project received for being an original production. The producers of The Last Broadcast have denied that Cannibal Holocaust was a major influence. Nonetheless, the film was cited by director Paco Plaza as a source of inspiration for the found footage films REC and REC 2. Cannibal Holocaust has been regarded as the apex of the cannibal genre, and it bears similarities to subsequent cannibal films made during the same time period. Cannibal Ferox also stars Kerman and Pirkkanen, and star Giovanni Lombardo Radice says it was made based on the success of Cannibal Holocaust. Cannibal Ferox has also been noted as containing similar themes to Cannibal Holocaust, such as comparison of Western violence to perceived uncivilized cultures and anti-imperialism. In a mixed review, film journalist Jay Slater claims: "Certainly a tough customer, Cannibal Ferox still fails where Deodato succeeds. [...] Lenzi attempts to tackle cultural defilement and racial issues, but Cannibal Ferox is nothing more than a shoddy exercise in sadism and animal cruelty." Reviewer Andrew Parkinson also notes: "At the end, there is a basic attempt to validate Cannibal Ferox, posing that old chestnut of whether civilised man is actually more savage than the uncivilised tribespeople."

Unofficial sequels to Cannibal Holocaust were produced in the years following its release. The titles of these films were changed following their original theatrical releases in order to associate the film with Cannibal Holocaust in different markets. In 1985, Mario Gariazzo directed Schiave bianche: violenza in Amazzonia, which was also released as Cannibal Holocaust 2: The Catherine Miles Story. In addition to the new title, Slater notes similarities between the score in The Catherine Miles Story and Riz Ortolani's score in Cannibal Holocaust. Previously known for his work in Mondo films, Antonio Climati directed Natura contro in 1988, which was released as Cannibal Holocaust II in the United Kingdom. In 2005, Deodato announced that he planned to make a companion piece to Cannibal Holocaust entitled Cannibals. Deodato was originally hesitant about directing his new film, as he thought that he would make it too violent for American audiences. However, while he was in Prague filming his cameo appearance in Hostel: Part II for Eli Roth, Deodato viewed Hostel and decided that he would direct after all, citing it as a similarly violent film that was given a mainstream release in the United States. Although the screenplay, written by Christine Conradt, was completed, a financial conflict between Deodato and the film's producer led to the project's cancellation. In 2013, Roth directed The Green Inferno, which takes its title from the fictional documentary produced in Cannibal Holocaust. Roth's film was intended as an homage to Cannibal Holocaust and other cannibal films from the same era. The film's influence has extended to other media as well. In 2001, Death metal band Necrophagia released a song entitled "Cannibal Holocaust" from the eponymous record. It was revealed in April 2020, that the movie would be getting a video game sequel called Ruggero Deodato, Cannibal. The game is being developed by Fantastico Studios and was expected to be available from November 2020 for Nintendo Switch, PlayStation 4, Xbox One, PC and mobile. However, in December 2020, the game was retitled Borneo: A Jungle Nightmare and delayed to Spring 2021, and later in 2024 under a new title, “Cannibal Tales”. The new title would still feature the “Borneo: Jungle Nightmare” story, but now under an episodic style of gameplay.