Background: Assessment of the presence and characteristics of sexual harassment in academic medicine is a global issue. Only limited international data are available so far. Methods: Aim: To assess the extent of sexual harassment and identify the perpetrators in the student population of the medical school of Münster, Germany. A survey was undertaken, using the Medical Women's International Association sexual harassment questionnaire translated into German. The anonymous online questionnaire was sent as a link to all medical undergraduates at Münster Medical School via a mailing list between 1 October and 30 November 2018. Identifying or potentially identifying data were not collected. Data were analysed by descriptive statistical methods such as categorical variables. Baseline characteristics, e.g. answers by male or female medical students, were correlated with their individual sexual harassment experiences and perpetrator groups by means of univariate analysis. Results: A total of 2162 medical students were asked to participate, with 623 (28.8%) completing the survey. Sexual harassment is a significant issue among medical students at Münster Medical School with over half (58.9%) of all undergraduates being exposed to sexually harassing behaviour. In total, 31.8% of all participants reported having experienced unwanted physical sexual contact such as unwanted physical touching, with 87.6% of the victims being female. Overall, 41.3% personally experienced verbal sexual harassment of which 87.4% were female. Furthermore, 8.5% of undergraduates faced forced sexual contact such as oral, anal or vaginal penetration, intercourse and rape, with all victims being female. Perpetrators in these cases were mostly male medical superiors (7.0%) and male patients (18.3%). In general, most perpetrators were patients, followed by medical superiors and educators, and less frequently by colleagues. Conclusions: Sexual harassment in medical education and the medical workplace is a significant problem in a German medical school. Most students experiencing sexual harassment are females. Female students also experience the more serious forms of sexual harassment more often.