Using a comparative perspective, this text analyzes the challenges that increasing ethno-cultural diversity present to educational systems in industrialized countries. In the first section we look back at the contentious history between formal schooling and certain social groups. The second part presents an analysis of the persistence of unequal treatment of ethnic minorities in different school systems. The third part point out the need to introduce the term «post-colonial minority» to enhance Ogbu’s theory on Cultural discontinuities and schooling. In the final section we discuss future research perspectives that may allow formal schooling to become more sensitive to cultural differences.