The identification of the city hierarchy of our home country raises numerous questions,which arises from the complexity of the settlement structure, as well as from the special urban development of the Carpathian Basin. The starting point has been the fact that there was a strong positive correlation between the position in urban hierarchy and the quantity (complexity) of the urban roles (Beluszky–Győri 2005.). The further aim of the study is to depict the network of cities of the interwar Hungary. First, I will study the emerging methodological issues, and I will also try to find solutions for them. The recent study published by Pál Beluszky and Róbert Győri (2005), which examines the 1910 conditions, provides a base to observe the changes in the mentioned structure until 1930. An important element of the present hierarchy study is to separate the downtown data from data of the periphery, as the classical homestead principle had already ceased to exist (Mendöl 1993., Timár 2006.). Another important methodological aspect of the study is the way my computer database is modelling and distorting the whole structure, as well as its levels. Using this method,the study of the interwar urban hierarchy can be put onto new methodological bases, which differ significantly from the earlier domestic research methods.