A multicenter randomized post-registration control-comparative trial included 94 patients with relapsing-remitting and secondary-progressive multiple sclerosis (MS) in the acute phase. Patients were stratified into 2 groups: patients of group 1 (n=53) received cytoflavin and basic treatment (trental and group B vitamins) and patients of group 2 (n=41) received only basic treatment. Based on the results of the 5-day treatment, each of these groups was stratified into 2 subgroups: patients of subgroup 1A (n=22) who demonstrated a positive effect continued to receive cytoflavin and basic treatment; subgroup 1B (n=31) received corticosteroids (metipred) as an add-on in the pulse- treatment regime; group 2A (n=14) continued to receive basic treatment due to the positive effect; group 2B (n=27) received corticosteroids as an add-on in the pulse-treatment regime. The treatment including cytoflavin, trental, group B vitamins and corticosteroids, was well-tolerated. The positive effect was due to the decrease in the need for corticosteroids: 41.5% of patients treated with cytoflavin and only 34% of patients receiving basic treatment did not need corticosteroids. The significant reduction of neurologic symptoms assessed with the EDSS was seen in patients treated with cytoflavin compared to the group which did not receive this drug. The clinical effect was observed in all patients. There was a decrease in lipid peroxidation levels and in the content of antibodies to basic myelin protein and the improvement of cognitive function.