A 68-year-old woman was admitted to the hospital because of abdominal fullness. Abdominal CT and magnetic resonance imaging scans revealed two large retroperitoneal tumors covering from the left subphrenic space to pelvis which had different internal structures. We performed laparotomy with a diagnosis of retroperitoneal liposarcomas. There were two tumors in the retroperitoneal space with capsule respectively, and these tumors were separated by the left kidney into the cranial part and caudal part. These cranial and caudal tumors had not invaded the surrounding organs and were relatively easily dissected. The cranial tumor was 2390g in weight, elastic-hard and segmented and the caudal one was 3730g in weight, elastic-soft and like a lipoma. Histological findings showed liposarcoma, well differentiated sclerosing type and well differentiated lipoma like form, respectively. Multicentric retroperitoneal liposarcoma is so rare that only three cases have been reported in the Japanese literature.