This article explores country-by-country differences in academic performance and attitudes towards school between students who repeated a grade in primary school, in secondary school or never repeated a grade. The analyses use PISA 2009 for 30 countries in which a relatively high proportion of students repeated a grade before the age of 15. The comparisons across countries and the examination of models of both academic and non-academic performance contribute to shed some light on the consequences of repeating a grade for students. The estimated associations suggest that in most countries examined, at the age of 15, students who repeated a grade in secondary school tend to perform better academically than do students who repeated a grade in primary school, but worse than non-repeaters. In terms of the measure of behavioural performance chosen for this analysis, attitudes towards school, in the majority of countries, non-repeaters tend to report more positive attitudes towards schools than primary and secondary-school repeaters, but the comparison between repeaters in primary and secondary schools shows less consistent patterns across countries. These differences are observed after accounting for background characteristics of the students and exploring some differential relationships between grade repetition and education outcomes according to student characteristics. The achievement and behavioural gaps among groups of repeaters may reflect differences in the development of academic and behavioural skills over the school years, as well as differences in the way these groups of students are treated across different educational systems.