We review our results of transplantation performed during the last 10 years in 65 children less than 15 years old: 32 parental grafts (group P) are compared with 35 grafts from well-matched (mean HLA-A,B mismatches: 1.7) cadavers (group C). Group P patients' survival is slightly but not significantly better than that of group C recipients (96.6 versus 82.7% at 5 years). Graft survival is significantly (P less than 0.02) better in group P than in group C (85.2 versus 51.2% at 5 years). At the end of the study, 3 grafts (2 from rejection) are lost in group P versus 14 (8 from rejection) in group C (P less than 0.01). The number of acute rejection episodes treated during the first 3 months is significantly lower in group P recipients. Epiphyseal osteonecrosis is observed in none of the patients of group P but in five of group C. Hypertension is significantly less frequent in group P than in group C. The results obtained in group P are attributed largely to a better non HLA-A,B compatibility, although the potential role of splenectomy performed in 25 recipients of group P and in none of group C cannot be excluded. Furthermore, the improved technical conditions inherent in living donor transplantation probably play an additional role. We conclude that in children the fate of parental kidneys is significantly better than that of cadaver transplants selected for their good HLA-A,B compatibility.