Among 149 kidneys transplanted in 141 children and teenagers aged 4 1/2 to 20 years, from November 1972 through December 1979, 70 (47%) were still functioning after ten years (67/145 cadaver donor grafts and 3/4 living related donor grafts). Medical and social status at the last follow-up visit (10 to 16 1/2 years after transplantation; m = 12 years) was analyzed. Patients were divided into five groups on the basis of glomerular filtration rate (GFR; ml/min/1.73 m2) and blood pressure (BP): 1) GFR greater than 80 ml and normal BP: 23 patients (33%); 2) GFR in the 60-80 ml range and/or high BP: 24 patients (34%/3) GFR in the 40-60 range: 6 patients; 4) GFR in the 15-40 range: 7 patients; and 5) hemodialysis restarted 10 1/2 to 13 years after transplantation. Mean adult stature was 155.7 +/- 10.4 cm in males and 149.8 +/- 10 cm in females. Osteoporosis was found in 88% of patients who underwent bone density quantitation. Twenty-four per cent of patients had aseptic osteonecrosis with variable degrees of impairment as a result. Chronic HBsAg carrier status was found in 37% of patients and was accompanied with persistent cytolysis in half the cases. Only one malignancy was seen (carcinoma of the urinary bladder in a child under cyclophosphamide). Six deaths were recorded between 10 and 13 years after transplantation; causes included septicemia (2 cases), cancer (1 case), hepatitis B (1 case), cerebral cystinosis (1 case), and unexplained sudden death (1 case).(ABSTRACT TRUNCATED AT 250 WORDS)