- California Doubling: None of the film was actually shot in Slovakia (or Amsterdam, for that matter). The entire film was shot in Czech Republic.
- Casting Gag:
- The first film features a cameo from Takashi Miike, director of Audition, a horror film that Eli Roth has publicly showered praise upon as a movie that genuinely scared him (let that sink in) and contained an ingenious Genre Shift that inspired him to structure the film in the same way.
- In the second film, the cannibal is played by Ruggero Deodato, the director of Cannibal Holocaust.
- Creator Killer: The second movie was this for Eli Roth. It was a modest hit at the box office and got bad reviews. Critics and audiences complained that it was too similar to the first movie and that they were getting bored with torture porn movies. Thankfully, he would rebound years later with The House With a Clock in Its Walls.
- Fake Nationality: Most of the actors in the first film were Czech, including those playing the Dutch Businessman (Jan Vlasák) and the German Surgeon (Petr Jani). The only actual Slovak actor in the first film was Barbara Nedeljáková (Natalya).
- Japanese tourist Kana is played by British-Chinese actress Jennifer Lim.
- The Italian Detective in II is played Luc Merenda, a French actor whose nonetheless very well known in Italy for starring in their poliziotteschi films of the 70s.
- Faux Fluency: Jan Vlasák, who plays the Dutch Businessman, didn't speak fluent English and learned all of his lines phonetically.
- Playing Against Type: Roger Bart, who, Desperate Housewives aside, tends to play bright and friendly roles as the villain of the second film. And he still mostly seems nice.
- Star-Derailing Role: The whole cast of the second movie suffered from this. Neither one of them appeared in any mainstream movies again. Vera Jordanova who played Axelle never appeared in another movie again, and this was only her second film. Jay Hernandez would later appear in Suicide Squad (2016), though.
Trivia / Hostel