The urban landscape is an interspersed mixing of residences, shops, theatres, parks, natural areas, and a multitude of other uses. From the early days of the central markets, to the planned downtown, to the heavily planned super-regional shopping complexes, the commercial areas within this urban landscape have evolved. There has been considerable research conducted on analyzing the commercial structure of urban environments in an attempt to better understand the nature of retailing and its resultant impacts on the geography of the city. This paper details the development of a GIS-based semi-automated method to detect commercial structure. The approach generated nearest commercial neighbour statistics as a measure of proximity between commercial locations. These were used as the foundation for clustering commercial operations into commercial areas.