The subject of research in this thesis is factors of service quality of passenger airlines. The aim of the work is to determine how a particular passenger airline creates its competitive advantage, that is, what kind of service it offers so that users are satisfied and tend to that particular company. Therefore, in the research part of the work, a primary research will be done in which user/passenger satisfaction will be connected with the level of service quality of individual airlines. Satisfaction as a whole is a complex concept that can be viewed as a process, cognition or emotional reaction. The same is associated with a particular element of the service or product or with the product or service as a whole. If the product or service meets the user's expectations, he will be satisfied, but if the product or service does not meet the user's expectations, a general negative impression will be created. The passenger airline market is one of the fastest growing, and accordingly it is extremely important to provide exceptional service to customers who become "loyal" in the process. On the other hand, user satisfaction is not a simple concept because each user is individual and values different factors. Some of the most important factors that influence the satisfaction of passenger airline users are the image of the company itself, the variety of services it provides and the price. Because of the above, companies should come up with good travel services, have consistency in developing new ideas and providing quality service, because with them they will ensure and attract new users. The paper itself will investigate the relationship between premium and low-cost passenger airlines, their advantages, disadvantages and challenges. All together will be imbued with their service quality factors. Primary and secondary sources of data will be used when preparing the thesis. Primary data will be collected through descriptive research - an on-line questionnaire (a deliberate random sample of respondents will be a minimum of 100 respondents), while secondary data will be collected from domestic and foreign literature, scientific and professional journals, articles and websites. The basic contribution of the thesis is manifested in a clearer understanding of the factors that influence the choice of the user and his attachment to a certain passenger airline. Next, in the research itself, the selection of passenger airlines will be seen, related to the airline they most often travel with, as well as the items that are important to them while traveling by air.