This study examines the degree to which New York City's immigrant students are segregated and how segregation varies across groups with differing language skills and from different countries. It notes how schools attended by immigrant students differed by student characteristics, teachers, and funding levels. After reviewing the literature on school segregation, the paper provides a statistical portrait of New York City's immigrant students and presents the research hypotheses and methodology. Academic and socioeconomic data from all children in New York City's public elementary and middle schools, linked to institutional information on the schools themselves for the years 1995-1996 and 1998-1999, indicate that foreign-born students as an aggregate group are not especially segregated from native-born students, at least compared to levels of segregation of non-white and poor students. While there are some differences in terms of peer and school resource environments, there is little evidence that immigrants as a whole experience large effects from segregation. Nonetheless, when viewing particular groups of foreign-born students (especially students from the former Soviet Union and Caribbean), there are significantly higher levels of clustering. School segregation appeared to benefit Soviet immigrants, while harming Dominicans. (Contains 46 references.) (SM)