Over the last several decades, a large body of research has sought to identify how stereotype threat affects the performance of people targeted by a negative stereotype. This paper presents a meta-analysis which aims to investigate how this phenomenon acts on elementary school children (kindergarten to fifth grade). Our main objective was to identify the age at which stereotype threat impacts school performance, and the conditions for its onset. We selected 17 relevant studies and used 25 effect sizes. The analyses of the empty model (random effect model, Viechtbauer, 2010) highlight a small significant effect indicating that elementary school children underperformed in a stereotype-threat condition compared to a non-threatening condition. The only moderator that was tested in the confirmatory analysis “activation type” was non-significant. However, the subsequent exploratory analyses revealed a significant effect of “grade level” and “stereotype type.” The results tend to show that stereotype threat acts negatively on the performance of 2nd to 5th graders, but does not impact the performance of younger children. Surprisingly, gender stereotypes do not seem to be the most harmful among these primary school participants. Indeed, the threat of the intelligence stereotype group harms a child’s academic performance considerably more.