We have analysed the causes of death in a group of patients with chronic renal failure--serum creatinine more that 225 mumol/l (2.5 mg/100 ml)--and find that there is an increased incidence of malignancy when compared with the fatality rates for cancers in England and Wales (p less than 0.0005). No patient in the series had received a transplant kidney or was therapeutically immunosuppressed for other reasons.