Fifty-one pediatric patients undergoing a first cadaveric kidney transplantation were followed for at least 2 years after grafting. They were divided into two groups: those treated with methylprednisolone plus azathioprine (AZA) and those treated with methylprednisolone plus low-dose cyclosporin A (CyA; median dose 109 mg/m2 per day = 3.4 mg/kg per day after 1 year). The steroid dosage given was significantly lower in the second group. The 4-year graft survival rate was 68% for the AZA group and 78% for the CyA group. Renal function did not differ significantly in the two groups; after 1, 2, and 3 years, the median 24-h creatinine clearance was 79, 69, and 51 ml/min/1.73 m2, respectively, for the AZA group and 78, 63, and 68 ml/min/1.73 m2, respectively, for the CyA group. Linear growth was similar in the two groups. We conclude that in pediatric patients the results of low-dose CyA immunosuppression do not differ significantly from those obtained with AZA in terms of graft survival, renal function, or growth.