Ten days after its premiere in Milan, the film was seized by the Italian courts, and director Ruggero Deodato was arrested and charged with obscenity. He was later charged with murdering several actors on camera, and faced life in prison. The cast had signed contracts requiring them to disappear for a year after shooting, to maintain the illusion that they'd died. Deodato contacted Luca Barbareschi and told him to contact the three other actors who played the missing film team. When the actors appeared in court, alive and well, the murder charges were dropped.
After seeing the film, director Sergio Leone wrote a letter to Ruggero Deodato, which stated, "Dear Ruggero, what a movie! The second part is a masterpiece of cinematographic realism, but everything seems so real that I think you will get in trouble with all the world."
The iconic poster image for the film shows a cannibal girl impaled on a stick. In court, Deodato explained that the girl sat on a bicycle seat attached to the pole's base, while holding a small pointed piece of balsa wood in her mouth. Fake blood was added afterward. He commented that the girl was unusually calm, and remained very still during filming.
When Carl Gabriel Yorke arrived in the Amazon for shooting, he wasn't given a script or any idea of what the movie was about. As soon as he arrived, director Ruggero Deodato shouted, "That's my star! Get him into makeup!" His first scene, shot almost immediately, was the amputation of a character's leg. In a later interview, Yorke said that in the jungle, he didn't know whether the film was a Hollywood production or a snuff film.
Immediately after a pig was shot and killed, Carl Gabriel Yorke botched a long monologue that Ruggero Deodato wanted to include in the movie. After rehearsing the line several times and doing fine, Yorke says he screwed up during filming because he heard the pig squeal and die. Retakes weren't possible because only one pig was "allotted" to be killed.
The father of the actor who played Miguel was murdered during filming. Production was delayed so the actor could go home for the funeral. When Prof. Monroe, Chaco, and Miguel are sitting outside the Yanomamo village, immediately after discovering the bone shrine, the actor is crying over his father's death.
Director Ruggero Deodato said he based the film on film he saw about a documentary crew who died while investigating cannibals in Africa. The documentary, showing incidents he depicted in the film, was destroyed after its discovery. An Italian cable network claimed it had a copy and was going to show it uncut. It never showed the film, but confirmed that they had a copy of the original.
A final subtitle at the end of the film states "Projectionist John K. Kirov was given a two-month suspended jail sentence and fined $10,000 for illegal appropriation of film material. We know that he received $250,000 for that same footage." is a reference to a distributor who screened the real cannibal footage that Ruggero Deodato based the film on.
In a 2005 interview, Carl Gabriel Yorke said that while rehearsing the sex scene with Francesca Ciardi, she suggested that they go out in the middle of the jungle and "actually do it". Yorke declined, saying he had a girlfriend back in New York. In 2009, Ciardi stated that the sex scenes were not simulated, and that she and Yorke were lovers off-screen during filming.
The animal deaths in the movie were real. The list of dead animals includes a coatimundi, a yellow-spotted river turtle, a snake, a tarantula, a young pig, and 2 squirrel monkeys. The monkey-killing scene was shot twice, so two monkeys were killed for that scene. The dead animals were given to the tribes for food.
Ruggero Deodato was inspired to make the movie after seeing his son watch a violent news report on TV. He noticed that the journalists focused on the violence, and believed that some news angles were staged to capture more sensational footage.
When the professor meets the shaman's son for the first time, the boy has a symbol "tattooed" on his nape. The same symbol can be seen on a truck passing by at the very last scene, right after the professor says "I wonder who the real cannibals are".
To create "The Last Road To Hell" sequence, Ruggero Deodato watched hours of execution footage. He later claimed that some of the footage he watched showed up in the "Faces Of Death" videos, and that he'd rejected it because it seemed fake.
In the ten days between its release and its banning in Italy, the movie grossed approximately $1.9 million ($5.2 million in 2012 dollars). Because of its infamy and several subsequent re-releases, some claim the film has grossed $200 million worldwide (not adjusted for inflation), though that has never been verified.