A 21-year-old Turkish man was admitted to our clinic for right knee pain, clicking and popping sensation in the affected knee for three months prior to his presentation. Difficulties in climbing stairs and disability during sports activities were the other symptoms of our patient. He reported no previous physical or surgical treatment for any other knee pathology and did not have any known history of trauma. On our patient's physical examination, atrophy of the quadriceps muscle was observed. Medial patellar apprehension test was positive and increased passive medial patellar mobility was observed when his patella was stressed medially. His gravity subluxation test was negative. His physical examination also revealed that medial subluxation of his right patella was more prominent in extension while weight bearing. We also noted patellofemoral hypermobility. He had no complaints related with his left knee. Conventional anterior to posterior, lateral and Merchant radiographs of our patient did not reveal any abnormality. Our patient was initially treated with physical therapy. A quadriceps strengthening rehabilitation program and neuromuscular stimulation focused on the vastus lateralis muscle and was continued for three months. After three months of rehabilitation, some improvement was achieved in his quadriceps strength and the medial translation of his patella was less than the pre-treatment level. However, he still suffered from right knee pain, which disturbed his gait pattern. As such, surgery was planned. Using a lateral parapatellar approach, we first performed direct lateral retinacular imbrication. We evaluated provocative patellofemoral tracking during flexion and extension of the knee by pressing on the inferior lateral pole of his patella. The achieved patellar stability was not sufficient and his patella was still moving medially more than 50% of its width. We dissected a strip of his iliotibial band approximately 1 cm wide and 4 cm in length, thus leaving distal base of the strip attached to Gerdy's tubercle. Using this strip, we augmented the patellatibial ligament. As the medial subluxation of his patella was more prominent in extension, we tensioned the strip in extension. Post-operatively our patient's knee was immobilized using a brace for six weeks. He was allowed to walk with partial weight bearing after the first post-operative day until the fourth post-operative week. During the first week he was allowed to perform passive knee extension and active assistive flexion exercises within a range of 0 to 90°. Full active range of motion exercises and full weight bearing was allowed after the third post-operative week. Quadriceps strengthening physical therapy focused on the vastus lateralis with neuromuscular stimulator was continued for three months after the operation. A home exercise program was also given to our patient. He was examined weekly for the first month. Follow-up visits were made by phone interview monthly and by clinical examination at intervals of three months. By the end of the sixth week of the surgery he achieved full range of motion. Meanwhile, full quadriceps strength was achieved at the end of the third post-operative month. Our patient did not experience any patellofemoral instability during his follow up examinations. During his last visit for follow-up examination, atrophy of his quadriceps muscle was completely resolved and both medial patellar apprehension and passive medial patellar mobility tests of our patient were negative. Gravity subluxation test was also negative. He was evaluated subsequently according to the clinical score and pain scale defined by Hughston et al. []. Our patient's pre-operative functional level limited performance of his daily activities. At the end of the first year, however, he was categorized as vigorous recreational. While he used to have severe pain, he described mild pain with competitive sports in the post-operative period and no pain with daily activities.