Is the perception of academic performance among peers biased to the disadvantage of students with migration background (MB)? What role does friendship among peers play for the perception of performance differences? In a quasi-experimental study, 9^th graders with and without MB attending school in Germany rated the performance of a comparison partner relative to their own performance after taking a mathematics test. Degrees of correspondence between perceived and actual performance in intragroup (both partners with or without MB) and intergroup (comparer or partner with migration background) situations were tested in multilevel analyses. In both intragroup comparison situations, students evaluated their partners’ performances benevolently. In contrast, in intergroup situations students with MB overestimated the performance of partners without MB relative to their own. Only students without MB judging partners with MB showed no such positivity bias. The pattern was replicated in the sub sample of friends, suggesting a subtle, yet powerful negative performance stereotype towards students with MB.