Enteric-coated mycophenolate sodium (ECMPS) has been developed as an alternative agent to mycophenolate mofetil (MMF), with the aim to provide reduction in gastrointestinal side effects. This open-label, single-arm, two-center prospective study sought to investigate the efficacy and safety of ECMPS used in combination with steroid and cyclosporine (CyA) in de novo and maintenance renal transplant patients with 12 months' follow-up. Twenty-one patients were recruited (mean age, 39 +/- 8 years) into the de novo group. Of these patients, 66% were male and 76.2% underwent living related kidney donation. The induction immunosuppression was ATG in 10 and basiliximab in 6 patients. At 12 months' posttransplantation, there was no graft or patient loss and two (10%) acute rejection episodes. None of the patients in this group discontinued the study medication due to drug-induced adverse events. One patient was excluded from the study because of recurrent oxalosis. Serum creatinine (SCr) levels at 3, 6, and 12 months after renal transplant were 1.30 +/- 0.3, 1.40 +/- 0.3, and 1.40 +/- 0.3 mg/dL, respectively. The maintenance group included 20 patients. Time posttransplantation (mean +/- SD) was 27 +/- 25 months. All patients in this group had been on maintenance azathioprine or MMF in combination with steroid and CyA. These patients were switched to ECMPS. They mean age was 36 +/- 8 years. Sixty-six percent of the patients were male and 57% received living donor kidneys. Acute rejection was nil, whereas two patients lost their grafts owing to chronic rejection in this group. Three patients were excluded from the study, one to discontinuation of the drug because of intractable diarrhea, the second to loss to follow-up, and the last case due to withdrawal of informed consent. Leukopenia was not observed in this group. The SCr levels prior to and at 3, 6, and 12 months after conversion to ECMPS were 1.80 +/- 1.0, 1.95 +/- 1.5, 1.50 +/- 0.8, and 1.60 +/- 0.8 mg/dL, respectively. This is the first phase IV study with ECMPS in the Turkish population. Renal function was preserved in both groups. Only 2.5% of patients were excluded because of side effects. Use of ECMPS in combination with prednisolone and CyA is an effective and safe therapeutic choice for both de novo and maintenance renal transplant patients.