The first Islamic primary schools were established in 1988 in the Netherlands, out of discontent withexisting schools. Currently, there are more than forty of such schools, which aim to educate children tobecome good Muslims, and improve the quality of education and children’s achievement levels. Sincethe very start, Islamic schools have been the cause of much controversy. Most concerns focus on theconsequences of self-segregation for children’s integration in Dutch society. This article examines theschools’ output in terms of attitudinal and behavioral factors (such as well-being, self-efficacy andsocial behavior) and achievement levels. Data are drawn from the 2005 cycle of the PRIMA cohortstudy and include 45,000 students at 450 schools. The results show that Islamic schools performsomewhat better than schools with a comparable socio-economically disadvantaged student population,but continue to lag considerably behind the average Dutch school. The general conclusion is thatIslamic schools are a long way from achieving their aims.