The thesis implements a Facebook advertising campaign for an event which is organized on 20th of September every year in Brussels, Belgium. The purpose of this campaign was to launch a new Facebook Advert in order to promote the main theme of the event “Sustainability”. The research was conducted as secondary research. The author of the thesis had been working as an intern in the non-profit organization Poseco and she took the information from the surveys, which were collected from Poseco. Based on the research and her work during the traineeship, she would like to suggest a new Facebook Advert for the event. The thesis starts by introducing the main goal of the project and this is followed by a discussion of relevant theories, particularly event marketing theory. Next, the author briefly describes Facebook event and the method of promoting it through Facebook. Subsequently, a Facebook Advert cam-paign is described to support the main idea of the thesis.