Today, mega-events are of increasing importance for the economic development of cities and countries around the world. The difference between an ordinary event and a mega-event is, of course, its size. It is about the size in many different areas that are presented and described in this paper. It can be defined as a consciously planned manifestation and celebration organized with special goals. Given that the paper analyzes two editions of the Olympic Games, it is important to note that the task of the organizers is to create a sports spectacle that will leave more positive than negative consequences on the environment. Bidding to host the Olympics is a complex and long-term process that should be approached seriously and responsibly. There is a direct connection between mega-events (in this case the Olympics) and tourism. All host cities during the organization of the Games create many accompanying activities during the competition so that spectators, together with athletes from more than 200 countries, get to know the city, its culture and share common values and celebrate the Olympic movement. However, the lifespan of organizing and planning a mega-event is much longer than the event itself. All these activities are extremely important even after the mega-event is held, for it to be considered a complete success. Certain strategies and efforts are needed for host cities in order to create more beautiful and better-living conditions by organizing mega-events, and for the city to become as big competitor as possible in the tourist market and thus send a positive image to the world.