In this study the researcher has chosen to focus upon the multiple roles by which Event tourism has been playing for the tourism development of Addis Ababa city. Pure qualitative research approaches with an interactive thematic analysis to analyze classifications and to present themes (patterns) that relate to the data, were used to undertake the research. To undertake this study, both primary and secondary data was employed, Through the help of semi-structured interview, attempt had made to collect the necessary data from participant and visitor of Meskel Festivity event which was held on Sept. 26th and Addis Ababa city Culture and Tourism officials, Tour and Travel operators, Event Associate Managers and Event Advisers,. To analyze the already collected data, qualitative data was first grouped into the category they belong and thus narrated according to the meaning it bears. In addition to investigating the role of event tourism in the tourism development, the aim of this research is also to explore the practice of event tourism and to identify positive and environmental, economic, socio-cultural and political roles of event tourism in the tourism development by taking Addis Ababa city as a case study. The findings of this study gave rise to the fact that although event tourism can be used by event organizer and government as a tool for economic gain, destination development and branding, it can also bring negative impacts to the community if not properly planned and organized. A general conclusion is that events affect host communities mainly by constructing a destination image and by building community cooperation to event tourism which could intensify the tourism development of the city. In precise, the study revealed out that indeed event tourism has both positive and negative Economic, Environmental, Socio-cultural and Political role and contribution in the tourism development of Addis Ababa city.