Events are important motivators of the tourism industry and are often embedded in the development and marketing plans of destinations. Sport events became an increasingly important subcategory of 'event tourism' in the last decades, therefore the current paper aims to simultaneously analyze the positive and negative impacts of sport event tourism. As the actual political and economical situation shape in high level these events and correspondingly the host community, the participants, the local economy and the environment, these circumstances have to be researched on a regular basis. Given that, the highest impact on can be traced regarding mega-sport event tourism, the current research focuses mainly on these events, but not neglecting the importance of small-scale events on the market. The research methodology used is descriptive, based especially on bibliographic documentation over time: research articles, official impact reports, national and international statistics. Results indicate, that the last decade has brought several changes in the judgement of mega-event organization, more emphasis being on the implementation of sustainability principles, the reduction of negative social and environmental aspects that the events and the spectators can have on the host community, but still, many of these efforts are shown only on paper and less in practice.