A surgical approach is described for en bloc removal of a large renal mass, enabling easy removal of such a mass with early palpation and ligation of the renal pedicle and with the minimum of assistance. The principle underlying the approach is that of detaching the costal margin and the free ribs from the abdominal musculature. In the experience of the author the wound always heals by first intention. No complications have been encountered and the patients have been discharged from hospital within 10 days of operation.