Moments before the filming of the Chinatown scene a crew member was approached by a local Chinese person who pointed out to him that all the neon signs with Chinese characters were upside down. A frantic rigging crew proceeded to flip all the signs while the shooting crew shot in the direction of the newly flipped signs.
In his opening voiceover, Remy mentions a scientist who devised an experiment in which a cat would be locked in a box along a poison capsule that with an unknown possibility of bursting. This is a reference to the Austrian physicist Erwin Schrödinger's imaginary experiment to show the paradox that an isolated system cannot be understood by a fixed rule, but rather in terms of possibilities: thus, opening the box would alter the system, and therefore the outcome.
In 2003 screenwriters Eric Garcia and Garrett Lerner began collaborating with Miguel Sapochnik on a screenplay based on a novel being written by Garcia. The novel, titled 'The Repossession Mambo', was published in 2009.
It has been widely speculated that Repo Men's premise was lifted heavily from the rock opera/cult movie "Repo! The Genetic Opera". Both stories center around a character in a dystopian future tasked with reposessing organs for a villainous corporation. The opera predates this film as well as the book it was based on, "Repossession Mambo". However, apart from this basic premise, Repo! and Repo Men differ wildly, making such plagiarism accusations difficult to substantiate.
The third act of the film is very similar to the film Brazil, in which the main character is revealed to have not actually experienced anything as they have been hooked up to a computer simulation program that immerses them in a fight for victory. The only real difference is that in Brazil the main character is brought out of the simulation and discovers he has been captured whereas in this film Remy is in a coma after a fight in which his head was smashed.