This article uses data from three studies to examine changing reactions toward ethnic minority groups in the Netherlands (1979–2002). Using realistic conflict theory, Study 1 focuses on support for discrimination of immigrant groups in general. The findings indicate that this support is more widespread in times of high levels of immigration, when the unemployment level has recently risen strongly, and among cohorts that grew to maturity in times of large immigration waves or high unemployment rates. Studies 2 and 3 focus on changing feelings toward different ethnic out-groups in an ideological context (2001–2004) marked by a shift from multiculturalism toward assimilation. Study 2 showed that the shift toward assimilation negatively affected Dutch participants' feelings toward Islamic outgroups, but not to other minority groups. Study 3 used an experimental design, and the results showed that ethnic attitudes are more negative in an assimilation compared to a multicultural context. It is concluded that the structural and ideological social context is important for understanding people's changing reactions.