Objective. To study the efficacy of mexidol in secondary prevention of stroke. Material and methods: We analyzed 3400 patients with stroke which were stratified into 7 groups: patients with cryptogenic ischemic stroke (II), arterial hypertension, atrial fibrillation, metabolic syndrome, syndrome of sleep-induced obstructive apnea/hypnea, diabetes mellitus, vasculitis. The assessment of efficacy was based on the absence of repeated II within 5 years of therapy. Results. Mexidol reduced the frequency of repeated II both in patients without concomitant diseases and in those with arterial hypertension, syndrome of sleep-induced obstructive apnea/hypnea, vasculitis, diabetes mellitus, atrial fibrillation and metabolic syndrome. Conclusion. The reliable efficacy of mexidol in secondary prevention of stroke was found out.