Although hyperuricemia is a well-known side effect of cyclosporine A (CsA) treatment, there are contradictory data regarding the effect of tacrolimus on uric acid levels. The aim of this study was to examine the influences of CsA and tacrolimus-based treatment regimens on serum uric acid levels in renal transplant patients. We included 155 patients with normal allograft function (creatinine <1.5 mg/dL) who underwent renal transplantation between 1999 and 2002. For each individual, serum uric acid levels after renal transplantation were recorded at 1, 6, 12, 18 and 24 months throughout follow-up. The patients were treated with CsA-based (n = 73), tacrolimus-based (n = 47) or conversion from CsA to tacrolimus-based (n = 35) immunosuppressive regimens. Thirty-six (23.2%) of the patients were female and 119 (76.8%) were male. The mean age was 34.7±9.7 years (range, 14-64). Serum uric acid levels of CsA and tacrolimus groups at initial and 24 months were as follows: 6.3±1.6 vs. 7.9±1.9 mg/dL and 6.5±1.8 vs. 8.0±1.8 mg/dL, respectively. Both of the treatment regimens progressively increased the serum uric acid levels (p=0.000). Serum uric acid levels of the patients with treatment conversion from CsA to tacrolimus were 8.6±2.8 mg/dL before conversion and 8.1±1.9 mg/dL after conversion. There was no alteration in serum uric acid levels after the change of treatment (p>0.05). These findings indicate that tacrolimus offers no advantage as compared to CsA on the serum uric acid levels in renal transplant patients.