The profile of repeaters is often studied, but there is a research lack on whether grade repetition effects are homogeneous considering the student features. In this research grade repetition impact on secondary school in Spain is analyzed through an innovative approach. Propensity Score Matching is used to estimate the effects of grade repetition on academic performance according to sex, socio-economic status, school ownership and origin. The results indicate that the negative impact is especially significant among females, immigrants, students from vulnerable backgrounds and those attending public schools. These results highlight heterogeneous consequences of grade repetition, which calls for its re-evaluation.