Morphologic parameters were correlated with survival in 121 renal cortical neoplasms including 116 carcinomas and five oncocytomas. An increasing nuclear grade was generally correlated with a significant decrease in disease-free survival although no statistical difference was found between nuclear Grade 1 and 2 tumors. Similarly, a higher stage at diagnosis predicted a shorter disease-free survival. Renal vein invasion adversely affected prognosis only for high nuclear grade carcinomas. Papillary and spindled carcinomas, independent of nuclear grade, were associated with a significant decrease in disease-free survival compared to tumors with a solid pattern. Patients with large neoplasms (greater than 10 cm) had a significantly worse disease-free survival than patients with tumors 10 cm or less. The prognostic significance of tumor cell type is less clear. Patients with oncocytomas had the best disease-free survival compared with patients with tumors of other cell types. However, the difference in survival was not statistically significant for low-grade tumors, suggesting that nuclear grade rather than cell type may be the more important determinant.