Background: Dentists according to professional knowledge of the prevention, have a key role in providing a positive model for oral health-promoting behaviours. We aimed to investigate health behaviour of Iranian senior dental students in terms of oral self-care and tobacco use during a ten-year period to assess their preparedness to act as role models for health-promoting behaviours.Method: The study was performed in six dental schools selected through stratified cluster random sampling to have a representative sample of established (old) and new dental schools in Iran. Data were collected in four occasions in 2005, 2008, 2011, and 2015. Senior dental students (n=1185) were invited to voluntarily complete a self-administered anonymous questionnaire about their oral self-care and tobacco use. Recommended tooth-brushing habit (RTH) was defined as at least twice a day brushing with fluoridated toothpaste. Three separate questions about cigarette, pipe, and water-pipe use were applied to indicate the students’ tobacco use. Results: In 2005, 2008, 2011, and 2015, 22.5% (n=60), 26% (n=52), 28.5% (n=81), and 24.6% (n=51) of the students reported smoking, respectively. Women reported a better status in both tooth brushing twice daily and frequent use of fluoridate toothpaste than men did (p<0.001). Among male students, 42.2% (n=159) and among female students 14.9% (n=83) of the students reported current smoking. The trend of reported smoking had the least variation among female students. This was true also for male students regarding RTH.Conclusion: The status and trend of oral self-care and tobacco use among Iranian dental students calls for more emphasis on adopting health-promoting behaviours during dental education.