Ethiopian Airlines is one of the most successful organizations in Ethiopia; however, there is virtually no formidable data on determinants of relationship marketing. Therefore, the objective of this study is to assess the determinants of relationship marketing on overall relationship quality of Ethiopian Airlines. The study employed both quantitative and qualitative study approaches. Both domestic and international flight clients, who fly Ethiopian during the study periods, were respondents for the five Likert scale survey questionnaire. Semi-structured key informant interview was also conducted with employees of the organization. As the theory predicts, this study also confirms that conflict handling is the first strong contributor followed by commitment, communication, and trust. In addition to this, descriptive and interview results show that the airline relationship quality is good; sociable; and show good hospitality. While the airline is generally successful in maintaining quality relationship with its clients, certain problems such as poor conflict handling, unequal customer treatment, and delays in informing flight schedule changes require attention.