Tissue obtained from 102 renal tumours presenting over a 21-year period was reviewed in an attempt to identify histological features of prognostic importance. Statistical analysis showed the grade of nuclear pleomorphism to have a significant bearing on survival. Application of the proportional hazard model, and using the grade of nuclear pleomorphism as a baseline index, showed mitotic rate, pseudocapsule thickness and the presence of sarcomatoid tumour cells to have an independent association with survival. The presence of tumour cells with granular cytoplasm was correlated with outcome; however, this parameter was not independent of grade of nuclear pleomorphism. Tumour pattern, intensity of lymphocytic infiltrate, degree of fibrosis, necrosis and hemorrhage, and amount of haemosiderin and dystrophic calcification were found to have no association with survival.