The dictionary contains terms and concepts concerning the epidemiology of emergency situations. In addition, there are ten applications in the dictionary: a brief description of new infections detected in the XX-XXI centuries.; characteristics of syndromes during mass events; standard case definitions for topical infections; a number of guidelines and classifications. The dictionary is aimed at epidemiologists, microbiologists, parasitologists, infectious disease specialists, health care organizers, scientists and practical doctors of any specialty, medical workers of the Ministry of Emergencies. The dictionary will be useful for students of medical universities, residents, as well as students of secondary medical educational institutions.