Torsion of a communicating hydrocele is extremely rare, and the cause is unclear. We report the case of a 3-year-old boy referred to us with acute scrotum. Operative findings revealed torsion of a communicating hydrocele with a 360-degree rotation of the distal end. We performed surgical excision of the necrotic cystic mass and high ligation of the peritoneal communication. A high index of suspicion is required for the correct diagnosis and treatment of this condition, which should be included among the causes of acute scrotum in childhood.