Seventy-two patients with renal carcinoma (RC) in a solitary kidney or bilateral synchronous tumours underwent parenchyma-sparing excision of their neoplasms. This was performed in situ in 51 and extracorporeally in 21 kidneys, with a complication rate respectively of 17 and 43%. The 5-year survival rates were 78% for unilateral disease, 48% for bilateral synchronous and 38% for bilateral asynchronous disease. Survival correlated with P category, grade and diameter of the tumour. Vascular invasion and spindle cells indicated a poor prognosis; the position of the tumour, oncocytic elements, calcification, lymphocytic infiltration or the predominance of clear cell or granular cells did not influence survival.