The current study investigated pre- and in-service teachers' reactions to interethnic exclusion in Germany. Using hypothetical scenarios, we examined a sample of 482 teachers (84 males, 398 females; 59% pre-service teachers, 41% in-service teachers) as observers of exclusion among students. In these scenarios, we varied the ethnic origin of the excluded student (German vs. Turkish) and the background information, providing participants either with no additional background information or with information specifying that the excluded student had shown prior norm-violating behavior (insult of another student). We assessed the teachers’ evaluations of the scenarios and their anticipated reactions. The aim of the study was to replicate and extend previous research on teachers’ reactions to social exclusion. As expected, the analyses revealed a strong effect of the background information on teachers’ evaluations and reactions. The teachers evaluated exclusion as much more acceptable and were less likely to intervene in the scenarios with negative background information compared to those without additional information. Teachers seem to view exclusion in these situations as an understandable consequence of norm-violating behavior. However, in contrast to our expectations, the ethnic origin of the excluded student in the scenarios had no impact on teachers’ reactions. That is, situational information seems to be much more important for teachers’ reactions to social exclusion than the ethnic origin of an excluded student.