Planning and organizing the functioning of health care institutions is a priority area of activity of their founders. The purpose of such management activities is to ensure the timeliness, quality and completeness of medical services provided to the clients of the institution. At the same time, an important step is to predict the needs for medical services in future periods of time. Forecasting should be carried out taking into account the socio-demographic, medical and behavioral characteristics of persons – potential consumers of medical services and the characteristics of the population structure of the territory in which the medical institution operates. Thus, the object of research is the processes that arise during the analysis of operational and retrospective statistical, medical and social, expert and other data to determine the forecast values of the levels of demand for certain medical services. The results of the analysis should become the basis for making management decisions on planning and organizing the activities of health care institutions in future periods.In the course of the research, a systematic approach, methods of mathematical modeling and other general scientific methods were used.The research result is a developed method for forecasting the demand for medical services in future periods of time. The method consists in the implementation of four sequential stages of the analysis of the initial data. In this case, it becomes necessary to solve the problems of clustering, classification, identification and forecasting. The accuracy of the predicted values depends on the choice of methods and algorithms for solving the problems posed and on the completeness of the initial data. As a result of applying the method, it is possible to obtain:аdivision of persons – potential consumers of medical services into groups in accordance with their socio-demographic portraits, medical data and behavioral characteristics;– relationship between the number of educated groups and the demand for various medical services;– predicted values of the number of groups, as well as the demand for medical services.The results can serve as a basis for making managerial decisions on organizing the activities of medical institutions in future periods of time.