Multimedia communication through social media has been experiencing constantly growing significance in the field of airline marketing. The aim of the research presented in this paper was to find out and, with the help of both qualitative and quantitative analyses, describe the way YouTube is used by airlines. The research was conducted in the form of a comparative study with the objective of identifying the difference between YouTube performance of full-service carriers (FSCs) and low-cost carriers (LCCs). The intention was to identify which factors influence the effectiveness of airline marketing conducted via YouTube an as well as the way in which they do it. Analysis of selected data was facilitated by social media analytics tool SocialBakers, content analyses and a correlation analysis of YouTube metrics, selected on the base of previous research results. The research data were collected twice during the year 2017 in order to reflect changes over time. Research results showed that FSCs build their YouTube channels more systematically than LCCs. FSCs offer a substantially wider range of video topics and often sort out topics of their videos in a more detailed way. Regarding the basic metrics of YouTube channels (total number of views, number of subscribers), FSCs surpass LCCs significantly. One reason for their much higher rate of views is the fact that FSCs use celebrities more frequently, and frequently they offer high-quality impression/relationship airline presentation.