A retrospective analysis based on Robson's tumor stage classification was performed on 56 patients with renal cell carcinoma who had undergone radical nephrectomy through a lumbar flank approach and 35 who had through a transperitoneal approach. The 5-year survival rates of patients with nephrectomy through the lumbar approach for Robson's stage 1, stage 2 and stage 3 were, respectively, 93.1, 70.4 and 60.0%. In comparison, the respective 5-year survival rates of patients with nephrectomy through the transperitoneal approach for Robson's stage 1, stage 2 and stage 3 were 90.5, 72.2 and 25.0%. As a result, there was no significant difference in survival rates between the two surgical procedures for any of the three Robson's stages. It is further suggested that the lumbar flank approach for radical nephrectomy does not result in poorer prognosis than does the transperitoneal approach, though transperitoneal and thoracoabdominal approaches have been generally recommended.