The results of kidney transplantation in juvenile-onset diabetic patients were compared to those of an age-matched control group of non-diabetic patients, all of whom were transplanted with kidneys from living related donors during the period 1977-1982, and managed by the use of conventional immunosuppression. The 5-year actuarial patient and graft survival rates did not differ significantly between the groups: 79% and 68% in diabetic patients and 88% and 72% in non-diabetic patients, respectively. The graft function was stable in both diabetic and non-diabetic patients. Early surgical complications in both groups were few. Peripheral vascular insufficiency leading to amputation occurred only in diabetic patients, while hyperparathyroidism was recorded only in non-diabetic recipients. Primary cytomegalovirus infections were more common in diabetic patients. Providing good graft function was achieved, heart complications were a minor problem in both patient groups. However, cardiovascular complications were a leading cause of death in patients whose graft failed. The initial hospital stay was, on average, one week longer in diabetic patients, but the accumulated hospital stay in the three years following transplant was twice as long (1 month per year) in the diabetic group as in the non-diabetic. Rehabilitation during the last six months of follow-up was good in both groups and about 60% of diabetic and 90% of non-diabetic patients were working full- or part-time. Thus, the prospects for survival and rehabilitation were similar in diabetic and non-diabetic patients in the 5 years following transplant, but at a higher price in diabetes.