objectives Well-designed studies on the impact of a family medicine rotation on medical students are rare, and very few studies include a qualitative component. This study aimed to determine the improvement of medical students' knowledge, communication skills and attitude towards primary care and explore their perceptions after rotations, in comparison with a control group.methods We used a mixed-methods design, comprising a pre-test-post-test comparison between a sample of trained students who took family medicine rotations and a control group and a qualitative survey. The measurement of improvement included (i) multiple choice question testing, (ii) objective structured checklist examinations, (iii) self-reporting and (iv) interviews and focus group discussions. Data were collected from August 2017 to June 2018.results There were 696 students in the trained group and 617 controls. The two groups' baseline scores in knowledge, communication skills and attitude were not significantly different. Knowledge covering five domains of family medicine (Pearson's r from 0.6 to 0.9) improved significantly, as did attitudes towards primary care in the trained group. There were no differences in communication and counselling skills between the two groups for four situations, but for two-health check-ups and mental health care-skills were significantly improved (Pearson's r from 0.28 to 0.43). The qualitative survey showed highly positive feedback from trained students.conclusions The family medicine rotation significantly improved students' knowledge and attitude towards primary care and some communication skills. Further studies should investigate students' interest in and career choice for this discipline.keywords family medicine rotation, primary care, knowledge, attitude, skill, pre-test and post-test comparison, qualitative survey, Vietnam Sustainable Development Goals (SDGs): SDG 3 (good health and well-being), SDG 17 (partnerships for the goals) *This article is part of a series of papers created in honour of the 40th anniversary