The present paper reports the clinical results from cases of renal cell carcinoma with vena caval tumor thrombus. Fifty patients were entered into the study between 1980 and 1989. The primary tumor and vena caval tumor thrombus were completely removed in 39 (78%) patients, and 41 (82%) received postoperative treatment. The overall 12-, 36-, 60- and 90-month actuarial survival rates were 72, 41, 19 and 10%, respectively. Only tumor stage affected survival, however, other factors such as tumor grade, nodal status, metastatic status and level of vena caval involvement not affecting it. Postoperative interferon (IFN) treatment affected survival, whereas degree of curative surgery did not. The results of our study were, however, examined retrospectively in several institutes. Further investigation of the postoperative treatment for renal cell carcinoma with vena caval tumor thrombus will be necessary.