OBJECTIVES Over the past 20 years, development of antiretroviral (ARV) therapy for HIV-infection has been dynamic, with continuous development in existing new ARV drug-classes as well as the introduction of new ARV drug-classes with a new mode of action. Maraviroc (MVC) represents the first oral licensed CCR5 co-receptor antagonist. The aim of this study was to estimate the cost-effectiveness of a strategy of testing and treating with optimized-background-therapy (OBT)+MVC according to tropism test results, compared to treating with OBT alone from the Mexican payer's perspective. METHODS A four-state Markov model was performed to estimate health and economic consequences during a time horizon of five years(6-month cycles). Effectiveness measures were progression-free-months (PFM) and quality adjusted life years (QALYs) gained. Transition probabilities and utilities were obtained from a systematic review employing international published literature(MOTIVATE-1 and -2 trials included). MVC 150mg/day BID was used and OBT therapy could include up to six different ARV. Resource use and costs were obtained from 637 randomized hospital records from the Social Security Mexican Institute(IMSS) and official institutional databases. Costs include outpatient and inpatient services, drug, tropism test, etc. The model was validated according to international guidelines. Probabilistic sensitivity analyses were performed employing second-order Monte Carlo simulation. Acceptability curves were constructed. RESULTS MVC+OBT showed the highest number of estimated PFM and QALYs (56.1 and 4.29) vs. OBT alone (34.5 and 2.96) (p<0.05). Although MVC+OBT showed higher mean expected costs(US$50,028.5±US$852.8) than OBT alone (US$27,846.1±US$700.2) (p<0.05), the incremental cost-effectiveness ratio(ICER) per QALYs resulted in US$15,384.6[CI95% US$9,307.6-US$23,076.9]. Sensitivity analyses showed that MVC+OBT could be a cost-effective treatment compared with OBT alone with a probability over 80% using accepted thresholds (US$12,500-US$37,500). Component analyses and net monetary benefits showed the robustness of these results. CONCLUSIONS MVC is a cost-effective option improving current ARV efficacy in Mexican individuals with few active treatment options.