Patellar misalignment is more common than usually supposed; many patients learn to live with this affection without seeing a doctor. A large number of open surgical procedures were described for treatment of misalignment of extensor mechanism of knee. We want to present our method which consisted in arthroscopic lateral release and augmentation of medial retinaculum. We had 47 patients with femoro-patellar misalignment treated with this method. The results were appreciated by clinical and radiological criteria (patellar glide test, patellar tilt test, Macnab scores, Merchant angle). The follow-up was two years. Only 17% had recurrence of clinical signs.