Intra-abdominal lymphangioma was first recognized when an autopsy case was recorded in 1507 by Benevieni. It has heen known as rarely occurring disease and seldom diagnosed directly or even suspected preoperatively. They occur along the gastrointestinal tract from duodenum to rectum and commonly found in the mesentery of small bowel. Because they have no pathognomic symptoms, signs and laboratory and radiologic findings, they are usually found in explorative laparotomy or incidental findings during some other operative procedures. Authours clinically investigated 10 cases of intra-abdominal lymphangioma that we treated at the Catholic University Medicial College from 1982 to 1989. We obtained following results; 1) The age distribution was 3 month age through 79 year of age and the sex ratio in male and female was 2:3. 2) The involved sites were small intestine (50%), large intestine (20%), peritoneum (10%), greater omentum (10%) and retroperitoneum (10%) in that order. 3) The size of tumor was varied from 5 cm to 25 cm and they contained serous or lymphatic fluid. 4) The cyst excision was treatment of choice and the intestinal resection with cyst excision was performed in intestinal lymphangioma.