OBJECTIVES: Identification of the better drug for immunosuppression following renal transplantation. METHODS: Efficacy data sources included completed comparative randomized clinical trials of cyclosporine microemulsion (Sandimmun Neoral, CsA) and tacrolimus (Prograf, Tac). Costs were derived from the wholesale prices of the study drugs (international drug distributor Shreya, as of 25 September 2006). Costs of other medicines with the exception of calcineurin inhibitors (Mycophenolate Mofetil, corticosteroids, Azathioprine), transplantation surgery, diagnostic laboratory procedures, and pharmacokinetic monitoring of blood concentrations of drugs were considered constant and left out of calculations in this comparative study. RESULTS: Analysis of randomized clinical trials has revealed similar efficacies for both analyzed treatment options, whereas the safety profile of tacrolimus is more of a problem: the frequency rates of the new onset post-transplant diabetes mellitus for CsA and Tac are 26.5% and 33.6%, respectively, according to Vincenti F. (2005), or 9.8% and 15.4%, respectively, as reported by Keown P. (2004). The rates of diarrhea in the study of Levy G. (2005) were 14% in the CsA group and 29% in those treated with Tac. This study evaluated the costs of initial and maintenance immunosuppression with Sandimmun Neoral and Prograf, which were approximately 22,600 roubles vs. 58,700 roubles for initial therapy and 176,300 roubles vs. 952,300 roubles for one-year maintenance immunosuppression, respectively. The amount of money saved annually with the Sandimmun Neoral-based maintenance immunosuppression regimen was found to be about 776,000 roubles per transplant recipient per year. CONCLUSION: Sandimmun Neoral is the leading alternative for immunosuppression following renal transplantation, i. e. it is preferable from a clinicoeconomic perspective.