Patellar ligament ruptures are difficult to treat, and require transfer of good quality tissues for an effective reconstruction. In this study the contralateral patellar ligament was chosen in preference to other types of graft. A graft was taken from the opposite knee (length 16 cm, width 8 mm) composed of a block of tibial bone, middle third of patellar ligament, block of patella, and quadriceps tendon. The bone blocks were embedded in slots made on the anterior surface of the patella and the tibia. The method of fixation allowed exact positioning as regards the patella height, and was sufficiently strong to allow immediate mobilisation and full weight-bearing. A series of 13 knees was operated on between October 1988 and July 1990, with a mean post-operative follow-up of 8.6 months. The technique was used twice following total patellectomy and once following total knee arthroplasty. This operation, without any complications from the donor site, produced a stable knee, corrected the extensor lag, and resulted in a mean post-operative flexion of 91 degrees.