OBJECTIVES: The current prevalence of Multiple Sclerosis (MS) in Slovakia ranges from 100 till 150 cases per 100 000 population Being a typical chronic disease with tendency of progression, MS can have a great impact on quality of life (QoL). The objective of this paper was to find out the level of QoL in patients with MS in Slovakia. METHODS: The primary method used for the analysis of QoL was the presence of disability period and combined questionnaire consisting of 4 parts: A. Demography and socioeconomics (13 items), B. Generic questionnaire (SF-36), C. Visual scale (4 items), D. Complementary (information and habits, 13 items). There were 2 groups of patients. Group A: 41 (29 women, 12 men) patients were treated by conventional therapy. Group B: the 41 (32 women, 9 men) patients were treated by moderns disease modifying treatment and biological therapy (Betaferon, Avonex, Rebif, Tysabri, Gilenya, Copaxone). The average age in the group A was 50.59 vs 41.82 years in the group B. RESULTS: Disability was 9,39 months per one patient per year in group A vs 5,02 in group B, loss of income was 123 vs 165 € per person, the expectations of the future was 2,39 vs 2,41 (in the five degrees scale). Present level of QoL was identified as 5.29 vs 4,34 on the scale of 10, while in the time of the MS diagnosis it was 3,29 vs 2,15. QoL was 8.68 vs 8,17 in the time without SM and 9,24 vs 8,29 in the total optimal state of health. CONCLUSIONS: The treatment of MS by conventional or disease modifying therapy (DMT) had a significant impact on QoL. The modern DMT had the higher statistical influence as on physical health (45,65 vs 28,23) so on mental health (51,65 vs 33,01) in comparison with the patients treated by conventional therapy.