Background: There is a shortage of general practitioners in Japan. With the revision of educational guidelines, general practice (GP) education has improved. However, the amount of education on GP in medical schools remains inconsistent. This study examined the relationship between medical students’ amount of GP-related education and their subsequent choice of GP majors. Methods: A retrospective cohort study was conducted in a teaching hospital in Japan. Participants were residents in the hospital. The exposure comprised compulsory lectures and training time for community-based medicine in medical schools. The outcome included participants choosing GP majors after their initial 2-year junior residency. Results: Fifty-one participants were included in the final analysis. Of these, 14 majored in GP and 37 in non-GP after their initial 2-year junior residency. Of the participants who took GP lectures for 18 hours or more, 11 chose GP majors, and 18 chose non-GP majors (risk ratio, 2.78; 95% confidence interval [CI], 0.88–8.79). Of the participants who underwent training for 12 days or more, 10 chose GP majors, and 16 chose non-GP majors (risk ratio, 2.40; 95% CI, 0.87–6.68). Conclusion The results do not support the association between the amount of compulsory undergraduate education for community-based medicine and the subsequent increase in the number of residents choosing GP majors in Japan. Educators would do well to explore different approaches, such as improving the quality of education to increase the number of GP residents. Further research is needed to reach more definitive conclusions.