The goal of the research is to analyze the dynamics of the clinical picture at multiple sclerosis (MS) patients living in Rostov region, who got the disease over the 1965 to 2010 period. The clinical data of 505 MS patients have been analyzed (age, gender, MS onset peculiarities, speed of MS progression, the time of reaching 3,4 and 6 EDSS scores). Worsening of the natural MS course over recent decades in population of Rostov region has been identifed. Taking into account the multifactor nature of multiple sclerosis, the fact of worsening can be explained by the increase of negative environmental infuence, which should be considered while medico-prophylactic organizations.