A sixteen-year-old male had symptoms referable to the posterior lateral compartment of the knee, specifically the region of the fabella. The features included intermittent pain in the posterolateral region accentuated by knee extension, localized tenderness over the fabella and no restriction of range of knee motion. The symptoms and signs of peroneal nerve palsy were not observed. The arthroscopic findings showed no articular hyaline cartilage face on the fabella and no inflammatory changes of the synovia. Partial resection of the fabella was done. The patient had complete relief of symptoms following surgery. The etiology of the pain may have been related to friction between the gastrocnemius tendon and the fascia.