According to literature liposarcomas account to less than 0.1% of all human tumors, 13% of which are localiced retroperitoneally. Authors describe two cases of giant retroperitoneal liposarcoms treated in their department. CT findings and the course of the disease discussed. Conlusively authors remark of high probability of microscopical residual disease with need of patients' follow up with eventual reoperation and adjuvant radiotherapy.