Purpose. In this study, a model is developed for making purchasing decisions by consumers on the travel agency market. Method. Research on the purchasing process by tourists was carried out applying the diagnostic sur- vey method. Making efforts to ensure that research on the behaviour of consumers regarding tourist services and determinants concerning participation of Polish society in tourism are characterised by reliability, the selection of the sample was purpose-specific, while the control variables were region, gender, type of residence (city, village) and age. The community structure was determined as 0.01% of the entire Polish population (precisely, 3,071 persons). Data from the surveys were developed in the Statistica 13.3 program using the logistic regression model. Findings. Prior travel traditions, fashion and desire to rest influence the need to travel. Stimulating the need for travel is necessary to start the purchasing process by a potential consumer of tourist ser- vices. When choosing a travel agency, potential tourists are mainly guided by a wide range of tourist services catalogues, the number and attractiveness of last-minute offers, as well as trip safety. How- ever, to attract loyal customers, a travel agency should primarily take care of after-sales contact, send birthday and holiday wishes to its clients, efficiently respond to all types of queries, and quickly and reliably respond to complaints. They should also make sure the website of their travel agency is in- teresting. Research and conclusions limitations. The characteristics of the participants constitute a limita- tion, as they all come from Poland. Therefore, future research must replicate this study with residents from other geographical and cultural contexts to generalise the present findings to Europe. According to some researchers, using multiple regression analysis and null hypothesis significance testing is not an appropriate scientific practice. Better results are presumed to be obtained by using asymmetric case outcome modelling. Practical implications. The research results may be helpful for travel agency executives and other tourism entrepreneurs. Knowing the factors that influence the choice of a travel agency and the cor- rect after-sales contact with the tourist will help tour operators gain regular customers. Originality. The innovativeness of the work concerns developing a new graphic model of tourist be- haviour on the travel agency market. To indicate the determinants of travel, factors influencing the purchase process and the choice of travel agencies, and how the post-sale contact between tour oper- ators and tourists should be conducted. Type of paper. In the article, the results of empirical research are presented, based on which the theoretical model of tourist behaviour on the travel agency market was created. Keywords: consumer behaviour, tourist behaviour, travel agency, logistic regression