Work in two distinct disciplines, urban geography and sociolinguistics, readily points out the multiethnic and multilingual character of metropolitan areas. However, there is still demand for studies which establish the language structure of modern cities. For the purposes of this pilot study, we focus on the Detroit Metropolitan Area (DMA), Michigan. Geographical Information Systems (GIS) technology together with census data were used to arrive at an adequate description of the spatial distribution of languages currently spoken in Detroit and its immediate surroundings. Data from the 2000 US Census are entered into a GIS system and presented visually with a subsequent analysis of the emerging spatial patterns. Due to limitations of the data, we had to restrict the mapping to languages used at home. The study suggests one possible model for the initial stages of mapping the multilingual city; moreover, the data analysed here provide the infrastructure necessary for further research on phenomena such as language shift and language death as well as other aspects of a dynamic multilingual situation. (Contains 5 tables, 7 figures and 8 notes.)