Background:The key method to let people follow a healthier lifestyle and to prevent chronic noncommunicable diseases is health promotion. Students in the medical field have to play a crucial role as in restoring and promoting health. Objective(s):The present study was carried out to assess health promoting lifestyle and self-efficacy among fourth grade medical students at Alexandria Faculty of Medicine, as well as to identify factors affecting their lifestyle in health promotion. Methods: A cross-sectional survey on 609 undergraduate fourth year medical students at Alexandria Faculty of Medicine during the academic year 2018-2019 was carried out. Participants were interviewed at the time they attended Community Medicine Department according to the faculty schedule. General Self-Efficacy Scale (GSE) and Health-Promotion Lifestyle Profile (HPLP II) questionnaires were the research tools used to identify student's health promoting lifestyle and their self-efficacy status. Results: More than half of the studied medical students (57%) showed good self-efficacy. The mean score for health promoting lifestyle profile was 2.4 ± 0.36 out of 4. The highest mean scores were for interpersonal relationships and spiritual growth domains. However, the lowest mean scores were for physical activity and health responsibility domains. Having a good self-efficacy perception, being free from psychiatric diseases, as well as practicing regular physical exercise were significant predictors of a promoting lifestyle among the studied medical students. Conclusion: More than half of the studied students had good general self-efficacy status. The highest mean scores of health promoting lifestyle domains were for interpersonal relationships and spiritual growth domains. Therefore, creating supportive educational environment that values healthy lifestyle and its vital link to student performance is needed.