OBJECTIVES: Chronic myelogenous leukaemia (CML) is a progressive disease associated with significant health and economic burden.  This study estimates lifetime costs and health outcomes associated with dasatinib treatment for chronic-phase imatinib-resistant CML patients. METHODS: A Markov model was developed to estimate lifetime costs and health outcomes associated with the treatment of imatinib-resistant CML patients. Seven treatments were modelled: (i) dasatinib100mg, (ii) imatinib 400mg, (iii) imatinib 600mg, (iv) imatinib 800mg, (v) nilotinib, (vi) interferon-a, (vii) bone marrow transplant (BMT). Five initial best response rate categories were defined: no response, complete haematologic, partial cytogenetic, complete cytogenetic and molecular.  Prognosis was assigned to each category, according to disease progression and mortality.  Prognosis was also assigned to BMT patients. Unit costs were drawn from national databases, and multiplied by resource use (driven by response level and disease status) to estimate total costs.  Health benefits were measured using quality-adjusted life years (QALYs), based on the patient’s current health status and level of response.  Univariate and probabilistic sensitivity analyses were conducted to estimate the confidence around the results. RESULTS: Dasatinib resulted in 6.425 QALYs, at a total cost of £314,413, per patient.  QALYs and costs for comparators were as follows: imatinib 400mg, 1.485, £135,326; imatinib 600mg, 2.394, £173,705; imatininb 800mg, 5.910, £350,365; nilotinib, 6.235, £228,576; interferon-a, 1.664, £6,764; BMT, 4.738, £302, 937.  Incremental cost-effectiveness ratios (ICER) for dasatinib against competitors were as follows: imatinib 400mg, £36,251; imatinib 600mg, £34,907; imatinib 800mg, dominant; nilotinib, dominant; interferon-a, £38,877; BMT, dominant. CONCLUSIONS: Dasatinib was more effective than imatinib 400mg, 600mg 800mg, nilotinib, interferon-a and BMT in the treatment of chronic-phase imatinib-resistant patients CML.  The analysis estimates dasatinib treatment to be less costly than imatinib 800mg, nilotinib and BMT, dominating these treatments in the cost-effectiveness analysis.  Dasatinib is therefore a cost-effective treatment option for patients in the CP of CML.