Given the wide use of peer assessment, especially in higher education, the relative accuracy of peer ratings compared to teacher ratings is a major concern for both educators and researchers. This concern has grown with the increase of peer assessment in digital platforms. In this meta-analysis, using a variance-known hierarchical linear modelling approach, we synthesise findings from studies on peer assessment since 1999 when computer-assisted peer assessment started to proliferate. The estimated average Pearson correlation between peer and teacher ratings is found to be 0.63, which is moderately strong. This correlation is significantly higher when: (a) the peer assessment is paper-based rather than computer-assisted; (b) the subject area is not medical/clinical; (c) the course is graduate level rather than undergraduate or K-12; (d) individual work instead of group work is assessed; (e) the assessors and assessees are matched at random; (f) the peer assessment is voluntary instead of compulsory; (g) the peer assessment is non-anonymous; (h) peer raters provide both scores and qualitative comments instead of only scores; and (i) peer raters are involved in developing the rating criteria. The findings are expected to inform practitioners regarding peer assessment practices that are more likely to exhibit better agreement with teacher assessment.