Torsion of an epididymal cyst is a very rare condition. We present a case of torsion of an epididymal cyst in a 13-year-old boy. The patient presented with acute scrotal pain. Scrotal ultrasonography showed a 38 x 35 x 30 mm fluid-filled mass within the caput of the left epididymis. Histologically, the cells of the epididymal duct were necrotic. To our knowledge, this is the second case report in the literature.