OBJECTIVE To evaluate the immediate and long-term results of a radical surgical technique in the treatment of renal tumours with extensive involvement of the inferior vena cava (IVC). METHODS Seven patients with extensive involvement of renal tumours into the IVC were operated upon using a cardiopulmonary by-pass, hypothermia and cardiac arrest to facilitate surgery. Wide exposure of the IVC in a bloodless field permitted complete removal of all visible tumour in each case. Histological sections confirmed renal cell cancer in six patients and Wilms tumour in a 15-year-old girl. RESULTS All patients recovered well from their surgery with no major complications and spent one or two days in the Intensive Treatment Unit and an average of 13 days in hospital after the operation. Of the seven patients, four are alive and well with no obvious disease after an average follow-up time of 30 months (range 8-54). The other three patients have died from disseminated renal cancer. CONCLUSIONS This procedure provides good local control of the tumour and offers the only hope of cure in patients with this disease. In collaboration with the surgical cardiac team it can be safely carried out with acceptable morbidity and mortality.