Abstract Introduction The university period is often characterized as a critical period of vulnerability for smoking habit initiation. Objective The purpose of this cross-sectional study was to assess the relationship between religiosity and smoking among undergraduate students on health sciences courses. Methods A total of 336 students on four health sciences courses (occupational therapy, speech therapy, nutrition, and physiotherapy) completed a cigarette smoking questionnaire along with the Duke University Religion Index. Results Smoking prevalence was 8.3% among females and 12.7% among males. Prevalence among students who do not have a religion, but do believe in God, was higher than among those who do have a religion (16.3 and 6.3%, respectively). Organizational religious activity has a significant effect on smoking status. Conclusion The students have health habits that are not only motivated by the technical knowledge acquired on their undergraduate courses, since there was a possible influence of social norms stimulated by religious institutions on their attitudes, knowledge and practices in health.