This paper examines the growth of the Olympic Games against that of former host cities to understand whether this mega-event may have ‘outgrown’ its hosts. The increasing hosting requirements and governments’ expansive use of mega-events as tools for urban development would suggest that the ‘Olympic city’ – a term we use for describing the size of the Olympics as hosted in different cities over the decades – has grown at a faster rate than former host cities. The analysis contrasts historical indicators that capture the evolving size of planning for the event based on four dimensions – sport, spectators, marketing and costs – as well as the urban dimension of hosting experiences (venues and infrastructure) with city trajectories based on demographic and economic indicators. This is done through a longitudinal analysis of former Olympic host cities from the 1960s and 1970s and from which continuous longitudinal data are available: Tokyo, Munich, and Montreal. The findings indicate that the Olympic city has grown more strongly than these former host cities, although not uniformly across trajectories. This gives evidence for the need to review the size of mega-event impacts if they ought to continue to generate interest in hosting them in the future.