Torsion of a cyst within the tunica vaginalis is a rare entity and clinical course can easily be confused with other diseases that cause acute scrotum. We report a 6-year-old child with 3 days of acute scrotum findings. Patient had surgery with the suspicion of testis torsion. Torsion of a cyst within the tunica vaginalis was found intraoperatively. In pathologic evaluation, a necrotic funicular cyst was diagnosed. Two different mechanisms were reported for the reason of this disease: hernia sac protrusion in the hydrocele sac and bell-clapper deformity. Our observations were on the side of bell-clapper deformity. We aimed to share our findings with this report.