The present report describes an unusual case of rectal perforation. An 81-year-old female was struck by a truck while walking in the street, and she was sent to a local hospital where fracture of the right subtrochanteric femur was diagnosed. She was admitted, in stable condition, for planned orthopedic operation. Consciousness change and respiratory distress developed 6 hours later. She was then transferred to a trauma center where extraperitoneal rectal perforation was diagnosed. Despite empirical antibiotics and surgical intervention, the patient unfortunately expired 3 days later. Unusual mechanism and incomplete physical examination were the major causes of delayed diagnosis. This case report also discusses the mechanism, classification and management of rectal perforation.