Summary. This paper investigates the spatial distribution of employment in the region of Ile-de-France in 1978 and 1997. Exploratory spatial data analysis is used to identify employment centres and a sectoral analysis of the central business district (CBD) and sub-centres is performed. The results highlight a process of suburbanisation of employment in Ile-de-France between 1978 and 1997. A more polarised space emerges in 1997 than in 1978, with several employment centres specialised in different activities. Moreover, even if the spatial influence of the CBD declines over the study period, the CBD maintains its economic leadership by concentrating a large variety of high-order producer services. 1