In the last four decades in which the air transport sector has entered into a major development process, airlines have focused on improving their service performance in order to gain a competitive advantage. While different approaches are being used to measure the quality perception for the services, the use of Multi-Criteria Decision Making (MCDM) methods has become prominent in recent years. In this study, it is aimed to bring a new approach to the evaluation of service quality in firms by focusing on the air transport sector. In this study, one of the current methods, the CODAS method is used. The data set of 11 airlines, which are evaluated in terms of service quality performances according to 7 criteria, are analyzed. Sensitivity analysis is also performed to measure the stability of the results after the application.