Renal transplantation was associated with a lesser degree of morbidity than chronic dialysis treatment in a group of 48 patients with end-stage renal failure. Morbidity was defined as total days of in-patient hospitalization divided by total days of risk. The morbidity during chronic intermittent dialysis, with a mean observation time of 296.1 (20 to 2255) days, was 11.8%, whereas after renal transplantation, with a mean observation time of 1004.0 (131 to 2400) days, only 7.6% of all days at risk were spent in hospital. Morbidity rises to 38.1% during chronic dialysis if all dialysis days on an out-patient basis are considered as hospitalization days. Morbidity was lowest (3.8%) in patients sent home for the first time with a functioning graft. Cardiac complications and fluid lung were the most common causes for morbidity during haemodialysis treatment; morbidity after renal transplantation was mainly due to renal rejection and infections under non-specific immunosuppression. Social and occupational rehabilitation was better after renal transplantation than during haemodialysis treatment. It can be concluded from these data that with regard to the quality of life renal transplantation is the preferable alternative in the management of end-stage renal failure.