As British society has become increasingly multiethnic and multicultural, debate has grown regarding the advantages and disadvantages of ethnically segregated schools, with regard both to educational achievement and to multicultural accommodation. Compared with issues regarding the class composition of schools, however, little work has been done on the degree of ethnic segregation in schools, let alone its impact. The authors use a recently developed classification procedure to identify the degree of ethnic segregation in England's secondary schools in 2001, using a database that gives every student's ethnic identity. It is shown that, although there is considerable segregation for members of ethnic minority groups in London and a small number of other urban areas, elsewhere there is much more exposure of members of those groups to White students; White students are much more segregated, however. In general, the level of segregation in schools is greater than the residential segregation of the various ethnic groups.