The study, the results of which are described in the article, is devoted to analysing and substantiating approaches to the assessment and quality assurance of tourism services, which form their competitiveness, namely factors and indicators of quality. After all, the integration and globalization of the world society determine the development of tourism as a catalyst for these global processes, and world practice has proved that tourism can be an effective way to solve many socio-economic problems. The subject of the study is the peculiarities of assessing the quality of tourist services. Methodology. The methodological basis of the work is a system of general scientific and special scientific methods, mainly, in the process of research, there are used such methods as system-analytical and dialectical methods – for the theoretical generalization of the investigated material; structural and logical method – in systematizing factors and indicators of the quality of tourist services. The purpose of the article is a theoretical justification of approaches to the quality of tourist services and optimization of their quality assessment. In the research, approaches to the interpretation of the concept of quality are presented and analysed, features of services in general and tourism in particular are concentrated, and it is suggested to group and classify factors and indicators of their quality. The interpretation of the notion of quality is ambiguous, both in Ukrainian and in foreign literary sources, and depends on the point of view on this notion. In our opinion, the most thorough definition characterizes the quality of products and services as a complex feature that determines their suitability to the needs of the consumer. Taking into account the specificity of the term “service”, peculiarities determining the approaches to their evaluation are studied, such a service can be considered a product dominated by intangible elements and also there are separate material components. The peculiarity of tourist services is that they provide the satisfaction of financial and intangible (spiritual) tourist needs of the person, which includes transportation services, accommodation services, and other travel services, not related to transportation and accommodation. Awareness of factors that determine quality is the starting point for improving it. We carried out an extrapolation of factors of the quality of goods, tourism services as a special type of goods, and made their classification. Quality score is a quantitative or qualitative set of specific requirements for the characteristics (properties) of an object that make it possible to implement and verify them. To determine the quality level, we have suggested a classification of quality indicators of tourism service. Conclusions. Tourist service is considered as a specific activity aimed at creating the conditions for the effective realization and use of tourism product, which is the result of the purposeful activity of the tourist enterprise. Factors of the quality of tourist services should be grouped according to peculiarities of their manifestation (forming, restraining and storing), and managing individual determinants (tourism potential, material base, personnel qualification, marketing research on the relevance and life cycle of services, ongoing maintenance of facilities, timely overhaul of production capacities services, measures of ecological and economic stability, introduction of standards of service and analysis of their observance, material interest personnel, using the principles of quality system) can be directed to act on the overall quality. Indicators of quality of tourist services are pointers of their quality. Establishing the optimal value of a certain quality index (according to the classification suggested in the study) and its comparison with the actual manifestation of this indicator, one can characterize the degree of conformity of the tourist service to its requirements. The latter is aimed at improving the quality of tourist services, and, indirectly, the requirements to them.