The separate clinico-morphological features of nonorganic retroperitoneal liposarcoma (NRL) and their prognostic value were studied in 200 patients. The type of primary NRL is histologically erentiated in 65.5%, myxoid in 16.1%, dedifferentiated in 9.2%, pleomorphic in 4.6% and mixed in 2.3%. There is a positive elation between overall survival, lyposarcoma hystologic type < 0.007) and completeness of tumor resection (p < 0.0008). Differentiated and myxoid NRL with cell volume less than 5.0% are characterized by better prognosis. Myxoid NRL with cell volume more than 5.0%, dedifferentiated and pleomorphic NRL types are unfavorable prognostic factors. Radical surgical resectio leads to 5-year and 10-year overall survival of 57.5% and 7.8%. Palliative surgery lead to worse results with 3-year and 5-year overall survival of 50.0% and 31.8% respectively. Therefore, the most important prognostic factors in NRL are histological type and completeness of resection.