This paper focuses on the concept of the smart city and the factors that work for its formation. One of them is related to the size of the city. The concept of the “smart city” has been particularly widespread in recent years both within the academic community and more widely in the field of self-government and society itself. In this context, emerging ‘smart city’ strategies around the world, with an emphasis on ‘smart citizens’ and their role in shaping smart cities, are at the center of research, business and policy initiatives. Since the size of cities in Greece varies significantly, it is important to investigate whether this particular characteristic affects the process of transforming cities into smart cities. For this reason, the paper focuses on the investigation of the concept of the smart city and its specific components, in relation to the importance of size, through the conduct of a qualitative research on representatives of different sized municipalities in Greece. The results of the research highlight the fact that the idea of smart cities in Greek local society is more widespread in urban centers. In addition, in the smaller cities the daily communication and contact of the citizens with the representatives of the local authority is a primary way of citizen participation. Finally, the size of the municipalities under study seems to have a significant impact on issues related to staffing, resources, the operation of economies of scale, etc. and which determine the operational capacity of each municipality.