1. The overall patient and graft survival rates (83.6% and 82% respectively) up to 23 years posttransplant of the group who survived a minimum of 10 years is reasonably good regardless of the donor source. 2. The primary grafts that survived a minimum of 10 years and were lost during the subsequent 12 years (17.7%) were equally due to rejection and the death of the patient. 3. Rehabilitation of the long-term survivor has been very good. Cardiovascular disease is becoming a significant morbidity among pediatric-aged recipients reaching the thirties. 4. The causes of death after 10-year survival are evenly distributed among infection, cardiovascular disease, neoplasms, dialysis, and hepatic failure. 5. The selected studies of immunologic reactivities in the long-term survivors show their failure to generate significant killing against donor-specific antigens while displaying normal MLR response against donor and third party. Significant depressions in their ability to respond in vitro to soluble antigens was also demonstrated.