The aim of this study is to investigate if and how mega sport organizations like \nthe Olympics contribute to the countries’ economies as well as its citizens’ welfare through tourism. The World Bank relevant economic data set from 1990-2012 was used for the study. Australia, Greece and China’s tourism and national income figures analyzed by using Multiple Linear Regression Model. The Eviews8 program was used for the Chow Breakpoint Test. In addition Percentage Trend Analysis was applied to the whole data. According to our study, when Australia, Greece and China examples taking into account the Olympics have no positive or negative structural breakpoint effect on \nthese countries’ economic development and welfare. Even though one structural \nbreakpoint for Australia (Number of Tourists) and two for China (Number of Tourists and Tourism Revenue) were detected, they were not powerful enough to change the structure of the countries’ economic size (GDP) and welfare (GDP PC). It is very important for countries to have enough economic power to host the Olympics or similar \nmega events. The view that mega organizations such as the Olympics will bring automatic and positive results every time and therefore permanent contribution to the economy through image rise and tourism, must be checked and rechecked. Hosting the Olympics requires short and long term plans, calculations and feasibilities. How the \nrapidly changing technologies and transportation means will affect people and their travel preferences are very critical subjects to ponder upon.