OBJECTIVES: The Brazilian guideline for the treatment of CML is not clear whether to increase imatinib dosage or switch to dasatinib for imatinib-resistant patients. The aim of this study was to evaluate the value of dasatinib versus imatinib >400mg for treatment of imatinib-resistant CML patients (dasatinib 100mg vs. imatinib 600mg for CP and dasatinib 140mg vs. imatinib 800mg for AP and BP), from the Brazilian Health Care System (SUS) perspective. We also studied the value of dasatinib versus nilotinib. METHODS: A cost-utility lifetime Markov model was developed to calculate the incremental cost per Quality-Adjusted Life Year (QALY). Disease progression depended on the best treatment response rates taken from dasatinib clinical trials. Transition probabilities and utilities were estimated from published literature. Drugs costs were obtained according to official prices and standard government discounting procedures.  Since nilotinib does not have a published price in Brazil, the lowest international price found on the internet was used. Resource utilization was based on clinical survey. Both costs and effects were discounted annually at 5.0%. The robustness of the results was assessed through deterministic and probabilistic sensitivity analysis. RESULTS:  In the base case, lifetime treatment resulted in dominance of dasatinib in CP versus both imatinib >400mg and nilotinib, and an incremental cost-effectiveness ratio (ICER) of about €52,000/QALY for AP and approximately €51,000/QALY for BP against imatinib. Sensitivity analysis showed pharmaceutical costs as the most important driver of the result. CONCLUSIONS: Compared to imatinib >400mg and nilotinib, dasatinib is associated with increased QALYs in all phases and lower overall costs in CP. So dasatinib is the dominant strategy for the treatment of chronic phase CML patients who are resistant to imatinib. Since clinical outcomes for imatinib 800mg for advanced phases are unsatisfactory, dasatinib 140mg is a reasonable option for imatinib-resistant CML patients in accelerated and blast phases.