The use of computers and mathematical methods in medicine in the USSR is outlined. In particular, application of computers in mass prophylactic examinations of the population, organization of wide-ranging dispensing services, automation of the diagnostic process, and computer-aided analysis of statistical data about the work of medical establishments is surveyed. Computers are also used in the field of medico-social investigations by the questionnaire method. Actual and possible uses of computers and data processing for the purpose of preventive medicine are discussed in greater detail, in particular for the purpose of activating human organism to resist diseases.