The aim of this dissertation is to provide a new perspective to the analysis of megaevent / host city relationship. The significance of the research subject depends on the interest in hosting mega-events such as the Olympic Games and the World Fairs, which generate a competition among cities. Turkish cities are recently being involved in this competition. In addition to that, mega-events have large-scale and long-term impacts on the built environment, which has not been thoroughly discussed in urban studies. The methodology which is based on a qualitative analysis comprises three steps: a historical analysis made on the Olympic host cities, and two case studies. The first case is Athens as the 2004 Olympic city, the second case is Istanbul as an Olympic bid city since 1990. This study recognizes but qualifies the concept of megaevent hosting. It is shown that mega-event hosting is a capacity-building process, whilst it has a potential to generate overdose investments problem in the built environment. The most significant conclusion of the study is that the ability of coping with this problem is correlated with the ability of absorbing the investments made.