Heath Ledger and Michelle Williams met and fell in love on the set of this film. She gave birth to their daughter, Matilda Ledger, shortly before the film premiered. However, they broke up in the fall of 2007, shortly before Ledger's sudden death in January 2008.
Jake Gyllenhaal is the godfather of co-stars Michelle Williams' and Heath Ledger's daughter Matilda Ledger.
When asked if he had any fears about playing a gay man, Heath Ledger replied that he was not afraid of the role, only that he wasn't mature enough to do it justice.
Heath Ledger adamantly shut down any homophobic jokes at the Academy Awards, as he felt it demeaned a really moving love story.
Heath Ledger, uncertain about the role when he was first offered it, was encouraged by his then girlfriend, Naomi Watts, to take it, immediately after they both read the script. After reading the script, Ledger said he would have flown to Taiwan to meet with Ang Lee in order to be hired for the role.
Rodrigo Prieto: The Mexican prostitute whom Jack picks up. Ang Lee asked him to play this part after judging the actor originally hired to be too short.