A data base study of 610 patients with recurrent or metastatic renal cell carcinoma was conducted in order to identify clinical characteristics that are prognostic for survival in patients with this disease. Multivariate analysis identified initial Eastern Cooperative Oncology Group performance status (0 versus 1 versus 2 versus 3), time from initial diagnosis (greater than 1 year versus less than or equal to 1 year), number of metastatic sites (0,1 versus greater than 1), prior cytotoxic chemotherapy (no versus yes), and recent weight loss (no versus yes) as important indicators of survival. Closer examination of the resulting model indicated that patients can easily be separated into five prognostic subgroups, the subgroups being defined by a simple function of the number of risk factors present [Eastern Cooperative Oncology Group performance status 1, recent diagnosis (less than or equal to 1 year), greater than 1 metastatic site, recent weight loss, and prior cytotoxic chemotherapy each counting as a single risk factor; and Eastern Cooperative Oncology Group performance status 2 and 3 counting as 2 and 3 risk factors, respectively]. Median survival for each of the five risk groups was 12.8, 7.7, 5.3, 3.4, and 2.1 months, respectively.