Objective: Dasatinib is indicated for the treatment of adults with CML with resistance or intolerance to Imatinib therapy. This study assessed the cost and cost-effectiveness of using Dasatinib when compared with Imatinib for the treatment of individuals with CML in México. Methods: A cost effectiveness life-time Markov model was used to calculate the incremental cost per life year gained (LYG) of the compared therapies. The model follows patients with CML considering the different phases of the disease, adverse events and the resource utilization so generated. There are three different scenarios depending on the phase (chronic, accelerated or blast) patients are started in the model. The Delphi Panel technique was used to provide estimates of the use of health care resources by CML patients within the setting of the Mexican Social Security Institute (IMSS). Transition probabilities and relative risks were estimated from published international literature. The base case analysis was from a health care perspective. Costs of drugs and other health care treatments were obtained from IMSS published information and were discounted at 3 %. A one-way sensitivity analysis was performed. Results: The economic evaluation showed that in the chronic phase Dasatinib was more effective (LYG difference of .71) and less costly (-USD$35,368) than Imatinib therapy. In the accelerated phase the incremental cost effectiveness ratio (ICER) per life year gained with Dasatinib was USD$36,366 when compared with Imatinib. Finally, in the blast phase the model showed for Dasatinib costs of USD$154,900 and effectiveness of 2.13 LYG and for Imatinib costs of USD$41,927 and 1.58 LYG. These findings were robust to deterministic sensitivity analysis. Conclusion: In México, Dasatinib is a cost effective therapy for the management of Imatinib resistant patients with CML in the chronic phase. In the accelerated and blast phases Dasatinib generates incremental costs because treatment continues indefinitely due to prolonged survival.