Chylous mesenteric cyst is a rare variant of mesenteric cystic lesions. Pathologically there is lack of communication of the main lymphatic vessels, resulting in cystic mass formation. Clinical presentation is diverse and can range from an incidentally apparent abdominal mass to symptoms of an acute abdomen. A 5-year-old girl presented with abdominal distension without pain. CT scan showed a huge and thin-walled cystic mass without solid portion. Laparotomy showed a $20{ imes}18cm$ sized huge mesenteric cyst containing chylous fluid. Pathological diagnosis was cystic lymphangioma.