Pasteurella pneumotropica is an important bacterial pathogen in both animals and humans. Most reported Pasteurella infections in humans involve skin and soft tissues, often after an animal bite, scratch, or lick to an open wound. We report a case of septic arthritis with Pasteurella pneumotropica in a diabetic and cardiopathic patient who was the victim of a rat bite in the street, with a good evolution after medical and surgical treatment.