Objective. Multiple sclerosis (MS) has a multifactorial etiology. To explore a role of genetic factors in the pathogenesis of MS, the authors studied familial cases of MS. Material and methods. For an analysis of familial cases, a database of 320 MS patients registered in Tomsk region since 1980 till 2014 was used. The following items for each patient were recorded: disease onset, manifestation of disease, duration of first remission, rate of progression of disease. Results and conclusion. Nine families with several members with MS were identified. In 2014, the frequency of familial cases in the MS population of Tomsk region was 4.7%. The prevalence of familial MS was 1.4 cases per 100.000 of people. The younger age at disease onset and higher rate of disease progression measured with the EDSS in parent-child pairs were identified. The most families with several members with MS were characterized by clinical polymorphism of onset, duration and rate of disease progression.