OBJECTIVES An adverse consequence of cancer is venous thromboembolism(VTE), manifesting as either deep vein thrombosis(DVT) or pulmonary embolism(PE). Compared with non-cancer patients, the incidence of VTE has been increasing in cancer patients over the past ten years and the risk of recurrent DVT and subsequent PE remains elevated. The aim of this study was to assess the cost-effectiveness of anticoagulant therapies to prevent VTE in Mexican patients with cancer from the payer's perspective. METHODS A six-state Markov model was performed to estimate health and economic consequences during a time horizon of one year (1-week cycles). Effectiveness measures were reduction in recurrent hospitalizations, reduced PE and DVT events; and avoidance of deaths. Markov transition probabilities were obtained from a meta-analysis employing international published literature. Comparators employed were warfarin(5mg/day); dalteparin(2500,5000,7500IU/day); enoxaparin(20,40,60mg/day); nadroparin(5700IU/day); unfractionated heparin plus warfarin(10000,30000,42000IU/day+5mg/day); acenocoumarol(4mg/day); and no prophylaxis intervention. Resource use and costs were collected from clinical records (n=7000) from Social Security Mexican Institute (IMSS) hospitals and official institutional databases. The model was validated. Bootstrapping techniques were used to develop probabilistic sensitivity analyses. Acceptability curves were constructed. RESULTS Incidence of PE and DVT were significant lower for patients treated with dalteparin(p<0.05). Regarding the reduction of DVT events, dalteparin 2500, 5000 and 7000 IU/day showed an Incremental cost-effectiveness ratio[CI95%] of US$45.81[US$44.9-US$46.8]; US$40.9[US$40.0-US$41.7] and US$37.8[US$37.0-US$38.5] against warfarin (gold-standard), respectively. Nevertheless, enoxaparin in all its presentations and no prophylaxis intervention alternatives were dominated by dalteparin. Dalteparin showed the lowest number of deaths and hospitalization re-admissions(for DVT and PE) when compared to other anticoagulant therapies(p<0.05) and showed a trend toward significant reduction of institutional costs in the short term. Second-order Monte Carlo sensitivity analyses showed the robustness of these results (ellipse-method). CONCLUSIONS Dalteparin demonstrated to be a cost-effective anticoagulant therapy to reduce incidence of PE and DVT events, deaths and recurrent hospitalizations in patients with cancer.