National audienceIndia whose population has recently reached the one-billion mark enjoys a rich and ancient census apparatus, which remains an under-utilized source for the study of contemporary socio-spatial dynamics. Our paper sums up the stages of a GIS project applied to the 75.000 localities of South India.<br />The emergence of GIS technology in a country like India comes up against many scientific, technical or institutional problems. Georeferencing of villages, for instance, required considerable effort because of the unavailability of reliable printed cartography. Similarly, systematic examination of the census data has underlined their shortcomings and called for corrections of all kinds. This article chronicles some of these conc...