To evaluate the role of post-operative irradiation in reducing local recurrence after surgical treatment of liposarcoma, 19 patients who were treated between July 1988 and June 1994 at Department of Orthopedic Surgery, Catholic University were studied retrospectively. The average follow up was 31 months. 1. There were 14 males and 5 females and an average age was 51 years old. 2. Thirteen cases were in extremities and buttock, 3 in neck, 2 in retroperitoneum and 1 in back. 3. Histologic types were 16 cases of myxoid type and 3 cases of well differentiated type. 4. Ten cases were achieved with wide margin and 9 with inadequate(intralesional or marginal) margin. 5. There were no local recurrence in 10 cases with wide margin, whereas 6(67%) local recurrences in 9 cases with inadequate margin. 6. Among 6 cases of local recurrence, 5 cases had been treated with post-operative irradiation. In conclusion, post-operative irradiation for inadequate margin(intralesional or marginal margin) was not sufficient to reducing local recurrence.