The retrospective and operative epidemiological analysis of leptospirosis morbidity on the administrative territories of the Southern Federal District during the period of 1990-2002 was carried out. The dynamics and tendencies of morbidity in individual administrative units of the region were shown. Materials on the negative influence of the emergency situation arising in the region as the result of the natural calamity in summer 2002 were presented. As shown in this work, timely decisions on the stabilization of epidemiological situation taken at the period of high flood and inundation in summer 2002 in the Southern Federal District and their efficient execution made it possible to keep the epidemiological situation in leptospirosis under control.