Britain has seen a significant increase in the size of its ethnic minority population over the past 20 years. Because of the relatively youthful age structure of the ethnic minority population, the percentage of ethnic minorities in the school age-groups is much higher than its share of the overall population. Given the very uneven geographical distribution of ethnic minorities, this has raised concerns over the extent of school ethnic segregation. This paper examines the changing distribution of ethnic minority secondary school pupils in England over the period 1999–2009. It shows that, while there have been big increases in the percentage of ethnic minorities in those local authorities with existing concentrations, with ethnic minorities comprising over 50 per cent of pupils in 24 urban authorities in 2009, the dominant trend has been one of an increase in the percentage of ethnic minority pupils across the board combined with the increasing diffusion of ethnic minorities across all local authorities, rather than increasing concentration in a small number of authorities.