Chronic ruptures of the patellar tendon are uncommon injuries. They are technically difficult to repair because of scar formation, poor quality of the remaining tendon, and quadriceps muscle atrophy and contracture. We report a case on the reconstruction of a chronic patellar tendon rupture. The reconstruction was performed 18 months after the injury, using an Achilles tendon allograft and reinforcing suprapatellar wire. At four weeks postoperative, the patient had attained 70degrees C flexion and 10degrees C extension lag. Nine months after the index procedure, the patient regained 130degrees C flexion and 5degrees C extension lag, and 85% quadriceps strength. The technique accomplished the preoperative goals of restoring quadriceps function and anatomic position of the patella as well as allowing early mobilization after surgery. Although this reconstructive procedure is technically demanding, the functional results obtained can be excellent. We recommend the use of this technique for chronic patellar tendon ruptures that cannot be primarily repaired.