OBJECTIVES: Tyrosine kinase inhibitors (TKIs), such as imatinib and dasatinib, have revolutionized treatment for chronic myelogenous leukemia (CML). Randomized trials suggest that TKIs differentiate according to both efficacy and rates of adverse events, which may translate in to differences in cost-effectiveness ratios. While some data exist on the resource use and costs of CML treatment in the US, no similar UK data exist .  However, differences in the management and costs of treatment of CML exist between the US and the UK. The objective of this study was therefore to calculate UK-specific resource use and costs estimates associated with the treatment of CML. METHODS: Using a questionnaire based on current treatment guidelines and clinical expert consultation, we elicited the opinion of six oncologists on the frequency of resource use (outpatient visits, laboratory tests, interventions and hospitalization). Estimates were stratified by disease phase (chronic, accelerated, or blast), treatment response status (responding or not) and treatment duration. Mean costs (minimum, maximum) in 2008 GBP were obtained from publicly available sources.  RESULTS: In the first three months of each phase, a patient responding to treatment was estimated to cost: £730 (£153, £1229) in chronic phase, £867 (£176, £1473) in accelerated phase, and £2659 (£590, £6014) in blast phase.  A patient not responding to treatment was estimated to cost £901 (£429, £1327) in chronic phase, £1012 (£437, £1416) in accelerated phase, and £4486 (£964, £7507) in blast phase.  Costs were higher for patients not responding to treatment, increased as patients progressed through disease phases, and decreased with increasing time in the phase. CONCLUSIONS:  Higher costs were associated with patients not responding to treatment in each CML phase. The estimates collected in the current study can supplement existing data on the economic burden of CML, and will serve as reproducibly-measured inputs for future models.