We describe a 3-portal endoscopic technique for the treatment of recurrent peroneal tendon dislocation. This new endoscopic approach is based on the 2-portal endoscopic hindfoot technique, as has been described in the literature before. By adding an additional third portal, 4 cm proximal to the posterolateral portal, the peroneal tendons can be safely assessed, and subsequently, the fibular ... [Show full abstract] groove can de deepened. We describe a patient with chronic peroneal tendon dislocation. The patient was successfully treated by means of this groove deepening technique with excellent results, both on functional improvement and pain relief, without complications. This endoscopic technique seems to be a good and safe alternative to the present open surgical procedures for treatment of chronic peroneal tendon dislocation.