In this study we evaluated the objective improvement of international preclinical medical students' knowledge in the subject 'Medical Psychology and Sociology' after attending a 3-day peer-led revision course. Using a pre-post-test-design, we found a significant improvement of post-results, compared to pre-results. This data verse contains our collected data as well as the R code used for statistical analysis. We also provide a RMarkdown file with our results. All participants are anonymised.