The authors describe entrapment of the popliteal artery within fragments of an open supracondylar femur fracture after reduction and stabilization with a retrograde femoral nail. At the time of fracture fixation, the loss of pedal pulses was noted, and an exploration of the popliteal vessels was performed. The popliteal artery was easily identified and dissected free after extension of the patient's lateral thigh wound. Following thrombectomy, blood flow to the distal extremity was restored and no postoperative vascular sequelae were encountered.