Amores Perros is a dramatic film that follows three different people whose lives become entwined when they are all involved in a car accident. Octavio is a young man who is in love with his sister-in-law. He can't stand the way his brother treats her, so he decides to become involved in dog fighting in order to earn enough money to flee town with her. His sister-in-law ends up taking Octavio's money and staying with his brother. Octavio is incredibly upset, but he remains in the dog-fighting business. One day his dog is shot by another dog owner, and Octavio stabs the man. He and his friend flee the scene only to become involved in the car wreck.
Octavio's car hits a car containing Valeria. Valeria is a beautiful model, but her leg becomes severely damaged in the car wreck. She is forced to use a wheelchair until she gets better. She stays in her apartment all day with her dog and her boyfriend, Daniel. Daniel is incredibly rich and successful. One day, Valeria's dog hides from her, and she becomes desperate to find the dog. Valeria tries to find her dog and only ends up injuring her leg again. The second injury is so severe that her leg must be amputated.
Octavio's injured dog is taken at the scene of the accident by Chivo. Chivo is a former guerilla fighter who has become a professional hit man. Chivo is going through some trials of his own, as he is attempting to reunite with his daughter. Octavio's dog ends up killing all of Chivo's stray dogs. Chivo ends up breaking into his daughter's house to give her some money. He also tries to leave a message for her, explaining why their family is broken up and apologizing. Chivo and Octavio's dog walk off into the sunset.