A 29-year old female patient was presented to the our department with mild intermittent lower abdominal pain. Otherwise she was healthy and she did not report previous exposure to toxic chemical agents. After physical examination, laboratory investigation and imaging study there was abdominal mass. Surgery was done the resected mass sent for histological examination that confirm the diagnosis lymphangioma. Lymphangiomas are congenital malformations of the lymphatic system that account for about 5% of all benign tumors in infants and children. The most common sites are the neck and axilla, which account for 95% of cases. Lymphangiomas in the peritoneal cavity are extremely rare, particularly in adults. Most commonly arising from the mesentery followed by the omentum, mesocolon and retroperitoneum. Preoperative diagnosis is often difficult due to the frequent silent clinical course. Radiological investigations are a useful diagnostic tool, but definitive diagnosis is confirmed by histopathology after a complete surgical resection