In an attempt to define the relationship among tumor size, stage and survival, the Cancer Incidence and End Results Committee of the American Cancer Society, Illinois Division, Inc. reviewed the records of 2,473 patients with a histological diagnosis of renal cell carcinoma. Tumor size was related to stage and survival. Larger tumors were generally associated with an increased stage (p < or = 0.0005) as well as poorer survival (p < or = 0.005). For Robson stages II, III and IV, tumor size may contribute additional prognostic information for patient survival.