Torsion of an epididymal cyst is an extremely rare cause of acute scrotum in children and in young boys. Its reported incidence is 5-20%. The treatment is usually conservative. Many cases (up to 60%) regress spontaneously, especially if below 3 cm. Few cases have been reported in Literature (7 cases/2018). We add our patient as eighth case. He was a 13-year-old boy who was admitted for acute scrotum. Ultrasound excluded torsion of the testis and he was managed for 5 day conservatively. Based on clinical history and physical exam, we decided to perform a prompt surgery that revealed a torsion of epididymal cyst that was confirmed by histological exam.