Cyclosporine and prednisone were used in combination to produce immunosuppression in 18 pediatric recipients of renal allografts. Ten children received cadaveric kidneys and eight received kidneys from living related donors. With a mean follow-up of 16.5 months (range 7 to 33 months), the patient survival rate is 100% (18 of 18) and the graft survival rate is 83% (15 of 18). Two grafts were lost for nonimmunologic reasons. Currently the group mean (+/- SE) serum creatinine concentration is 1.22 +/- 0.11 mg/dl and creatinine clearance is 69.3 +/- 4.79 ml/min/1.73 m2. Cyclosporine nephrotoxicity has not caused irreversible allograft injury nor led to graft loss in this population. The incidence of treated rejection episodes has been 39% (seven of 18). Only 39% (seven of 18) of children have required hospital readmissions since the initial transplant discharge. There have been no opportunistic infections. In the 15 children with functioning grafts, some linear growth has occurred in 10 of 11 prepubertal and two of four postpubertal patients. Cyclosporine and prednisone have constituted a safe, efficacious immunosuppressive regimen for pediatric renal allograft recipients. Longer follow-up will be necessary to confirm whether these advantages persist beyond 2 years.