A prospective trial of adrenocorticostertoid (steroid) withdrawal after pediatric renal transplantation was begun in 1990. Ninety-four pediatric renal transplant recipients were enrolled in our multicenter study. Immunosuppressive therapy with cyclosporine (CyA), methylprednisolone (MPL), and mizoribine (MZ) was started after transplantation. MPL was reduced to administration on alternate days in 69 patients (73.4%) and was withdrawn in 27 patients (28.7%). Rejection episodes occurred in nine patients (33.3%) after withdrawal of MPL. It occurred within 3 months after withdrawal of MPL in two patients and more than 6 months in the others. Among them, two patients lost the grafts. Thirteen-year patient survival rate and graft survival rate were 94.6 and 83.1%, respectively. Forty-four of the 94 patients reached their final height. Mean final height was 155.0 cm in males and 146.3 cm in females and their height standard deviation score was -2.6 s.d., the same as that at the time of transplantation. Management of growth retardation before transplantation and further reduction in the steroid dose after transplantation will increase the final height of children with chronic renal failure.