In this article, the three approaches for the delimitation of functional regions are presented based on daily commuting data: the labour market method, the commuting zone method and the commuting aggregation approach. The first two methods demand predefined centres while the functional regions are formed without predefined centres by the third method. These three approaches have been used for the case of the delimitation of functional regions of Slovenia considering only one spatial phenomenon, which is the daily commuting between the municipalities. The use of different methods is precondition for comparison and understanding of different approaches for modelling of functional regions. Functional regions might be the basis for numerous organizational tasks as well as development policies. They might be used as the starting-point for the administrative regionalization of Slovenia.