OBJECTIVES: In the UK, Chronic Lymphocytic Leukaemia (CLL) makes up 40% of all leukaemias in patients over 65 years. The objective of this UK-based study was to obtain societal preferences for “progression-free” and “progressive” stages of late-stage CLL, and selected treatment-related adverse events.  METHODS: A utility study, using the Time-Trade Off (TTO) method, was conducted in the UK with 110 members of the general public for a baseline disease state (before treatment), 3 primary disease states (Progression-free survival (PFS) response, PFS non-response and Disease progression) and 4 adverse event (AE) sub-states (PFS response with thrombocytopenia, neutropenia or severe infection, and PFS non-response with severe infection). Disease state vignettes were developed using literature and validated by expert CLL clinicians. Face-to-face interviews were conducted by trained interviewers.  The TTO scores were converted into a utility value for each disease state and disutilities were calculated for AEs. Visual Analogue Scale (VAS) scores were also obtained. RESULTS: All participants were included in the analysis. The mean utility scores from the TTO for the primary disease states were: baseline: 0.549; PFS response: 0.671; PFS non-response: 0.394; and progression: 0.294. The mean TTO utility (disutility) scores for the AEs were: PFS response with thrombocytopenia, neutropenia or infection, 0.563 (-0.108), 0.508 (-0.163), 0.476 (-0.195), respectively; PFS non-response with infection, 0.333 (-0.061). The VAS results were in line with the TTO results.  CONCLUSIONS: Overall, the utility was higher for the PFS state than for baseline, but decreased below baseline in non-response and disease progression states. AEs had an important impact on utility within the PFS response state. The severe infection AE appeared to have a greater impact on patients responding to treatment compared to non-responders, which may be related to the quality of life which is already low for the latter.