This empirical work studies the influence of immigrant students on individuals’ school choice in one of the most populated regions in Spain: Catalonia. It has estimated, following the Poisson model, the probability that a certain school, which immigrant students are already attending, may be chosen by natives as well as by immigrants, respectively. The information provided by the Catalonia School Department presents school characteristics of all the primary and secondary schools in Catalonia during the 2001/02 and 2002/03 school years. The results obtained support the evidence that Catalonia native families avoid schools attended by immigrants. Natives certainly prefer not to interact with immigrants. Private schools are more successful in avoiding immigrants. Finally, the main reason for non-natives’ choice is the presence of other non-natives in the same school.