OBJECTIVE:The aim of this study was to evaluate the effects of obstetric simulation training on undergraduate medical students to improve their self-confidence. METHODS: Fifth-year undergraduate medical students were invited to a 2-week course of simulation in obstetrics during their clerkship. The sessions included were as follows: (1) care for the second and third periods of childbirth, (2) partograph analysis and pelvimetry, (3) premature rupture of membranes at term, and (4) diagnosis and management of third-trimester bleeding. Before the first session and at the end of the training period, a questionnaire about self-confidence in obstetric procedures and skills was applied. RESULTS: A total of 115 medical students were included, of whom 60 (52.2%) were male and 55 (47.8%) were female. Comparing initial and final scores, the median results of the subscales "comprehension and preparation" (18 vs. 22, p<0.001), "knowledge of procedures" (14 vs. 20, p<0.001), and "expectation" (22 vs. 23, p<0.01) were significantly higher at the end of the training period in all items of the questionnaire than in the beginning. Differences were found based on the students' gender, i.e., female students had a significantly higher sum of scores than the male students in the initial subscale for "expectation" (median, 24 vs. 22, p<0.001) and "interest" (median, 23 vs. 21, p=0.032), and a higher sum of scores in the subscale for "expectation" (median, 23 vs. 21, p=0.010) in the final questionnaire. CONCLUSION: Obstetric simulation enhances the improvement of students' self-confidence in understanding both the physiology of childbirth and the obstetric care procedures. Further studies are needed to understand the influence of gender on obstetric care.