ABSTRACT Location decisions are often based on inaccurate information about potential locations. Decision-makers seem to be guided by their subjective interpretation of reality, not so much by reality itself. Twenty years ago this fundamental idea was the starting point for a research programme of the Faculty of Spatial Sciences of the University of Groningen, focused on the subjective rating of locations by Dutch entrepreneurs. Three extensive and identical postal enquiries were held, in 1983, 1993 and 2003. On this basis a comparison can now be made of the changing ‘mental map’ of Dutch entrepreneurs during those twenty years. The paper analyses the three maps, preceded by a short introduction about the behavioural approach in economic geography, which inspired the research project. The survey data are used in a factor analysis, to establish the basic influences that form the entrepreneurial mental maps. The basic dome shape of the maps did not change much. During 1983 to 1993 we witness a decrease of appreciation of locations on its West flank (the ‘old’ Randstad) while in 1993 to 2003 this decrease extends to the Eastern Randstad. Factor analysis suggests that three fundamental dimensions determine entrepreneurs’ judgments: potency, activity and evaluation. Potency may be understood as centrality of location. Activity is correlated to agglomeration. It is hypothesised that landscape and culture determine the evaluative dimension.