OBJECTIVES: To estimate the costs of multiple sclerosis according to severity of disease. METHODS: Total, direct and indirect costs were compared in 160 patients divided into three groups categorized by disease severity: stage I Expanded Disability Status Scale (EDSS <2.5), stage II (EDSS 3- 4.5) and stage III (EDSS >5). RESULTS: The majority of these patients (94%) developed relapsing- remitting MS.A minority of the patients (0.2-4 %) developed secondary progressive and primary progressive MS. Cost evaluation was performed from the societal perspective and covered the one-year period. The mean total cost/patient for one year was estimated at 27095, 27997and 31662$ for stage I, II and III, respectively. Both direct and indirect costs increased with MS progression. For indirect cost the main item was productivity loss. The mean extra medicine (treatments for  MS symptoms   and adverse effects of medications) cost/patient for one year was calculated at 19036 $ . CONCLUSIONS:  This study confirms that MS represents a high economic burden to patients and society, with direct costs greatly exceeding indirect costs. As costs increase with disease progression, treatment efforts should focus on patients in the early stages of MS .Disease support system that monitors a variety of common progressive signs for the MS individuals is a key element of a management program as well.