Objective: To evaluate the prevalence of and factors associated with experimentation with and current use of water pipes and e-cigarettes among medical students. Methods: This was a cross-sectional multicentric study involving a convenience sample of students from medical schools in most Brazilian geographic regions. Information about experimentation with and current use of conventional cigarettes, water pipes, and e-cigarettes; beliefs and attitudes toward tobacco products; religiosity; and demographics were collected by means of an online structured questionnaire. We used descriptive statistics and logistic regression to analyze the association of those factors. Results: Our sample comprised 700 individuals from four Brazilian regions. Prevalence of experimentation with and current use of cigarettes, water pipes, and e-cigarettes were, respectively, 39.1% and 7.9%; 42.6% and 11.4%; and 13.1% and 2.3%. Water pipe experimentation was higher among those who had a sibling (adjusted OR = 2.64; 95% CI, 1.24-5.61) or friends (adjusted OR = 2.33; 95% CI, 1.63-3.31) who smoke. The same occurred regarding e-cigarette experimentation: siblings (adjusted OR = 2.76; 95% CI, 1.17-6.50) and friends (adjusted OR = 2.47; 95% CI, 1:45-4.22). Curiosity and scent/taste were the major reasons for water pipe use and e-cigarette experimentation. Although 93% of the responders learned about health damages of smoking during medical school classes, 51.4% reported having experimented with at least one of these tobacco products. Most responders who reported feeling the presence of God/the Holy Spirit in their lives were never experimenters of water pipes (59.2%) or e-cigarettes (55.3%). Conclusions: There is a high prevalence of experimentation with tobacco products among medical students whose siblings or friends smoke, despite their knowledge about smoking harms.

Keywords: Education, medical; Health knowledge, attitudes, and practice; Electronic nicotine delivery systems; Smoking water pipes; Religion.