Duplications are rare congenital anomalies which can be found in the gastrointestinal system from mouth to anus. Bleeding, intussusception, intestinal obstruction, volvulus and malignancy can complicate cystic duplications. A perforated cecal duplication cyst was detected in a 7-year-old boy operated with the findings of acute abdomen. The cyst was totally excised and the case is presented as a rare cause of acute abdomen.. ©2005, Fırat Üniversitesi, Tıp Fakültesi