Bifocal disruption of the knee extensor mechanism is a rare injury. Bifocal proximal and distal avulsion fracture of the patella tendon is extremely rare in adults. Here, the authors report the case of an 84-year-old male patient who developed simultaneous avulsion fracture of the patella tendon from the inferior pole of the patella and the tibial tuberosity. Open reduction and internal fixation were performed, and at 12 months postoperatively, an excellent functional result was obtained.