IEA's International Civic and Citizenship Education Study (ICCS) identifies first- and second-generation immigrants, and hence may reveal patterns of segregation of immigrant students. From a comparative perspective, these may be analyzed to provide the distribution, concentration and spread of immigrant students among schools and countries. Here three methods of analysis were employed: (1) descriptive analysis, (2) construction of segregation indices, and (3) multilevel analysis. In general, countries do not implement systematic policies to concentrate or segregate immigrant students, although there are important differences between countries; instead there is a need to appreciate strong relationships between levels of segregation and inequality or human development indexes, and consider geographical, cultural and economic factors. Schools appear to have a limited effect in transforming attitudes toward immigration.