To estimate health state utility values (HSUVs) for multiple sclerosis (MS) by key demographic and clinical characteristics.Data from a UK prospective, longitudinal, cohort study of people with MS were used for analysis. Patient-reported outcomes on the EuroQol five-dimensional questionnaire (EQ-5D) and the six-dimensional health state short form (SF-6D) (derived from 36-item short form health survey), SF-36 were used to estimate HSUVs by age, sex, MS type, time since diagnosis, disease severity (Expanded Disability Status Scale score), and relapse characteristics.The cohort (n = 1,441) (11,778 returned questionnaires) was representative of the UK population with MS. Data indicated that primary and secondary progressive MS were associated with lower HSUVs than relapsing-remitting MS and that HSUVs decreased by disease severity. This was particularly apparent for the EQ-5D, with mean estimates ranging from 0.846 to 0.025 for Expanded Disability Status Scale scores 0 to 8, compared to mean SF-6D estimates ranging from 0.702 to 0.529. Experiencing a relapse in the previous 6 months had a significant impact on HSUVs, with mean decrements of 0.076 for the EQ-5D and 0.052 for the SF-6D.These findings demonstrate the negative impact of MS on health-related quality of life, especially as the condition progresses, and indicate the substantial influence of varying features of relapses on HSUVs. This is the first report of SF-6D values for a UK MS population and the first time that EQ-5D data have been presented in such detail for people with MS. The representative nature of the sample means that these data can be used to offer decision makers more precise estimates of the effectiveness and cost-effectiveness of MS treatments.