Changes in the intensity of ethno-racial segregation in the greater Paris metropolitan area over the last three census periods are analyzed. First, immigrants strictly speaking (persons who themselves immigrated) were studied in terms of national origin ; to this group were added all second-generation immigrants that could be identified by means of census information. Scale used is neighborhoods and municipalities in the greater Paris metropolitan area. Dissimilarity and isolation indices as well as concentrations by commune (municipality) show that the most intensely segregated immigrants are from North Africa, sub-Saharan Africa and Turkey, that segregation is increasing at a moderate rate, and that it is significantly more pronounced than socio-economic segregation while remaining well below racial segregation levels observed for United States cities. The vast majority of immigrants studied live in neighborhoods where they represent a minority, meaning they are living in residentially mixed situations, not ghettos.