The timing of renal transplantation in infants is controversial. Between 1965 and 1989, 79 transplants in 75 infants less than 2 years old were performed: 23 who were 12 months or younger, 52 who were older than 12 months; 63 donors were living related, 1 was living unrelated, and 15 were cadaver donors; 75 were primary transplants and 4 were retransplants. Infants were considered for transplantation when they were on, or about to begin, dialysis. All had intra-abdominal transplants with arterial anastomosis to the distal aorta. Sixty-four per cent are alive with functioning grafts. The most frequent etiologies of renal failure were hypoplasia (32%) and obstructive uropathy (20%); oxalosis was the etiology in 11%. Since 1983 patient survival has been 95% and 91% at 1 and 5 years; graft survival has been 86% and 73% at 1 and 5 years. For cyclosporine immunosuppressed patients, patient survival is 100% at 1 and 5 years; graft survival is 96% and 82% at 1 and 5 years. There was no difference in outcome between infants who were 12 months or younger versus those who were aged 12 to 24 months; similarly there was no difference between infants and older children. Sixteen (21%) patients died: 5 after operation from coagulopathy (1) and infection (4); and 11 late from postsplenectomy sepsis (4), recurrent oxalosis (3), infection (2), and other causes (2). Routine splenectomy is no longer done. There has not been a death from infection in patients transplanted since 1983. Rejection was the most common cause of graft loss (in 15 patients); other causes included death (with function) (7), recurrent oxalosis (3), and technical complications (3). Overall 52% of patients have not had a rejection episode; mean creatinine level in patients with functioning grafts is 0.8 +/- 0.2 mg/dL. Common postoperative problems include fever, atelectasis, and ileus. At the time of their transplants, the infants were small for age; but with a successful transplant, their growth, head circumference, and development have improved. Transplantation in infants requires an intensive multidisciplinary approach but yields excellent short- and long-term survival rates that are no different from those seen in older children or adults. Living donors should be used whenever possible. Patients with a successful transplantation experience improved growth and development, with excellent rehabilitation.