Over the past two decades, many studies have examined the relationship between perfectionism and academic achievement. However, these studies have yet to be systematically collated and meta-analysed. The purpose of the present study was to do so. A literature search returned 37 studies (N = 8901) and 156 effect sizes. Random-effects meta-analyses indicated that perfectionistic strivings showed a significant small to medium positive relationship with academic achievement (r[superscript +] = 0.24), whereas perfectionistic concerns showed a significant small negative relationship with academic achievement (r[superscript +] = - 0.08). One moderator of these relationships was the instrument that was used to measure perfectionism. This was particularly the case for perfectionistic concerns. The findings suggest that the relationship between perfectionism and academic achievement is complex with perfectionistic strivings potentially aiding and perfectionistic concerns potentially hindering students' academic achievement.