This work presents the results from a long-term model comparing the clinical and economic outcomes associated with different immunosuppressive protocols for in renal transplant patients. We calculated the cost of maintenance immunosuppression {ISM} in 970 kidney transplant patients, classifying them according to the combination of drugs used and whether the immunosuppression continued to be the same as initially indicated (primary ISM), or a later adaptation. Basic clinical data were also acquired on the through levels of drugs and the use and cost of the associated medication. The model was based on the results of a prospective, randomized study of 970 renal transplantation recipients receiving azathioprine based, calcineurin-based or sirolimus-based protocols either with or without monoclonal antibody induction; The model estimated that 5 years after transplantation, the proportion of patients surviving was 70% of the cyclosporine ME cohort and 79% of the tacrolimus cohort. The daily cost per patient related to steroids and azathioprine is very low (13.5$); the mean cost per patient and day for Cs, Tacrolimus (T) and MMF, was 5.1, 25.4 and 4.7 $, respectively. The use of anti-hypertensive medications was not significant between groups, while the use of hypolipidemic drugs was significant (p < 0.001). Renal transplant recipients maintained on tacrolimus have better short- and long-term outcomes than patients maintained on cyclosporine. The treatment of immunosuppression with T is more expensive than Cs based treatment but the difference is reduced with the advantages of use of low dose MMF in these patients