Medial patellofemoral instability is a rare, disabling condition that is often associated with the wrong indication for lateral retinacular release or overcorrection with medializing tibial tubercle osteotomy. It is an even less common complication after total knee arthroplasty (TKA). The lateral patellofemoral ligament is an important lateral stabilizer of the patella against medial subluxation or dislocation. Until now, no report in the literature has described lateral patellofemoral ligament reconstruction with a free gracilis tendon autograft. Furthermore, there has not been a single case report of lateral patellofemoral ligament reconstruction after TKA. The authors describe a novel technique for reconstruction of the lateral patellofemoral ligament in a symptomatic medial subluxated patella resulting from TKA and extended lateral release in a 62-year-old patient. The result 1 year postoperatively was deemed successful. Clinically, the patella was stable, with correct tracking, and radiologically the patella was correctly positioned. With a technique similar to that used for the medial patellofemoral ligament, the lateral patellofemoral ligament can be reconstructed with a gracilis tendon autograft to permit stabilization independent of resting scar tissue of the lateral retinaculum. This operation can be performed in a minimally invasive way, without opening the joint, therefore decreasing the risk of joint infection. The authors showed a successful clinical and radiologic outcome 1 year after lateral patellofemoral ligament reconstruction in a patient with medial patellar instability after TKA and lateral release.