An MMF-based immunosuppression has reduced the acute rejection rate in adults and in children in the early post-transplantation period. In the present study, pediatric renal transplantation patients on a CyA, MMF, and steroids regimen were prospectively evaluated. Patients with CyA, MMF, and steroid therapy without antibody induction were evaluated for surgical aspects, renal function, rejection, and survival, growth after transplantation, adverse events and medication discontinuation. Between February 2003 and May 2005, 21 kidney transplantation patients under 18 yr old were followed for at least 12 months. Within one year after transplantation, three patients developed four episodes of acute rejection (19%). Graft loss because of rejection occurred in one patient. One-year mean serum creatinine was 1.19 +/- 0.3 mg/dL. Mean calculated CrCl by Schwartz formula was 82.3 +/- 19.7 mL/min*1.73 m(2). Major adverse events included infections of the urinary tract and diarrhea, abdominal pain, and GI symptoms. No patients have discontinued the use of MMF. Good results in pediatric kidney transplantation can be achieved by using CyA/MMF/steroids. MMF is effective and relatively safe in reducing the incidence of acute rejection even without induction therapy 12 months after transplantation.