Mesenteric cysts are not uncommon in pediatric age group but giant lymphatic cysts of mesentery are reported infrequently. This is a report of six years old female who had vague abdominal pain with distension for two years. Investigations revealed a large cystic mass in abdomen. On exploration a giant lymphatic cyst in the mesentery of transverse colon found. More than 1500 ml of milky fluid was drained. The cyst was unilocular and appeared to be the collection of lymph (chyle) between two leaves of the mesentery of transverse colon. It is postulated that trauma to or malformation of lymphatics at the root of mesentery might have lead to this pathology.