OBJECTIVES: To estimate utility weights associated with CML-related health states among layperson respondents in three countries. METHODS: We elicited interviewer-administered time trade-off utilities with a 10-year time horizon for seven CML-related health states, from convenience samples of laypersons in Australia (n=79), the UK (n=100), and Canada (n=103). Standardized health state descriptions were derived in consultation with a panel of oncologists. Interviewers underwent training and used a single script. Mean utilities with 95% confidence intervals (CI) were calculated for each health state. A generalized linear model was used to determine whether utilities, adjusted for age and sex, differed by country. RESULTS: The mean age of the combined sample was 46 years and 46% of respondents were men. Mean (95% confidence interval) utilities among Australian respondents were: 0.85 (0.81-0.89) for chronic responders (CR), 0.68 (0.63-0.72) for chronic non-responders (CNR), 0.71 (0.67-0.76) for accelerated responders (AR), 0.40 (0.34-0.45) for accelerated non-responders (ANR), 0.44 (0.38-0.49) for blast responders (BR), 0.12 (0.09-0.15) for blast non-responders (BNR), and 0.52 (0.45-0.59) for adverse events (AE). Utilities from UK respondents were: 0.90 (0.87-0.93; CR), 0.72 (0.67-0.77; CNR), 0.77 (0.73-0.82; AR), 0.53 (0.48-0.57; ANR), 0.55 (0.51-0.60; BR), 0.29 (0.24-0.34; BNR), and 0.52 (0.46-0.57; AE). Utilities from Canadian respondents were: 0.72 (0.66-0.77; CR), 0.56 (0.51-0.62; CNR), 0.58 (0.52-0.63; AR), 0.44 (0.39-0.49; ANR), 0.38 (0.34-0.43; BR), 0.26 (0.22-0.30; BNR), and 0.34 (0.28-0.39; AE). Significant differences were observed between and among countries. CONCLUSION: These data demonstrate the deteriorating impact on quality of life assigned to disease states occurring through progression of CML. This is one of the first studies to identify systematic differences between countries in utility weight estimates for oncological health states. This observation adds to evidence from other disease areas that systematic differences exist in utilities between countries.