This study examines xenophobic attitudes of high school pupils. It answers the questions: To what extent do high school pupils from different ethnic backgrounds hold xenophobic attitudes? And to what are these attitudes related with interethnic contact? Scientific progress is made in three ways. Firstly, attitudes of high school pupils from both the ethnic majority (Dutch) and the ethnic minority groups (Turks, Moroccans, and Caribbean) are examined. Secondly, the impact of positive as well as negative interethnic contact within and outside the school environment is determined. And thirdly, hypotheses about interethnic contact are tested while simultaneously controlling for alternative mechanisms that explain xenophobic attitudes. The results show that most pupils have a low level of xenophobia. In addition, the level of xenophobia is less when pupils evaluate their interethnic contacts both within and outside the school environment as positive and higher when they perceive these contacts as negative. However, the impact of positive interethnic contact in class disappears or even reverses when multiculturalism is stressed more during lessons.