Director Bong Joon Ho often clashed with producer Harvey Weinstein, who frequently interfered in order to demand "his" version of the film. Among the many requests, the producer insisted on having the fish scene removed in favor of more action. Bong, who considered it his favorite shot in the film, was adamant to keep it in. He told the producer that he wanted to keep the shot for a personal reason, as a tribute to his late father, who was a fisherman. Upon hearing this, Weinstein said that family is very important to him, so he granted Bong to keep the shot. In an interview, the director said "It was a fucking lie. My father was not a fisherman."
Writer and director Bong Joon Ho had reservations about casting Chris Evans in the lead role, because of his muscular physique. He felt that as a resident of the extremely poverty-stricken tail section, Chris should not be especially physically fit. Costuming and careful camera angles kept Evans' physique from showing.
There was no additional lighting used while filming the torchlight fight scene.
Writer and director Bong Joon Ho explained that the protein block was made by combining seaweed, tangle, sugar, and gelatin. Jamie Bell hated it, while Tilda Swinton liked it.
The drawings in the tail section of Snowpiercer were illustrated by Jean-Marc Rochette, the original comic artist of the graphic novel Le Transperceneige.