OBJECTIVES: During the last decade, the introduction of new disease-modifying drugs (DMDs) for MS gave rise to a number of studies on the economic burden of the disease and the cost-effectiveness of different treatment options. Since these surveys were conducted before DMDs were established as part of standard treatment regimens, there is a need for up-to-date cost-of-illness studies that can be used for the economic evaluation of new treatments. Therefore, European Health Economics has conducted a European-wide, cross-sectional bottom-up survey on the costs of MS, involving at least nine countries. METHODS: The study used a standardised mailed questionnaire providing data on demographics, direct medical and non-medical costs, informal care needs, productivity losses, relapses, utility and fatigue. RESULTS: The results were analysed by country, both for the whole sample and by level of disease severity measured with the Expanded Disability Status Scale (EDSS). Patients were recruited by MS clinics and MS societies, and the response rate ranged between 35% and 72%. Overall, the study includes over 10, 000 patients. The samples per country are thus sufficiently large to analyse the change in costs and utility for all levels of disease severity. For example, in Sweden, the total annual cost per MS patient was estimated at €53,580, with costs increasing sevenfold for patients with severe disease compared to patients with no or very mild disability, from €16,338 to €116,502. DMDs were used by 43% of patients and accounted for 11% of total costs. In addition, analysis of variations across countries illustrates the impact of different healthcare and economic systems on patient management, total costs and distribution of resources. For example, services represented 29% of total costs in Sweden, due to a unique extensive home service available to severe patients. CONCLUSIONS: This alternative to institutionalisation reduces nursing home costs and informal care needs.