A tibialis posterior and flexor digitorum longus tendon rupture associated with a closed bimalleolar ankle fracture occured in a 30 years old man due to traffic accident. The tendon injury was not recognized before surgery but was diagnosed at the time of operation. The treatment was open reduction and internal fixation of the ankle fracture with primary repair of the ruptured tendons. one year postoperatively, he had a nearly full range of ankle and toes motion without pain and a radiologic normal longitudinal arch. This associated tendon injury, although rare, maybe first time in reviewed similar reports, should be considered in the management of ankle fracture because the tendon rupture could easily have been overlooked.