BACKGROUND: Smoking is currently accepted as a well-established risk factor for many oral diseases such as oral cancer and periodontal disease. Provision of smoking cessation care to patients with oral problems is a responsibility of health care professionals, particularly dentists and dental hygienists. This study examined the smoking-related perceptions and practices of dental school hospital-based health professionals in Japan. FINDINGS: A cross-sectional study design was used. The sample was formed from dentists, dental hygienists, physicians and nurses of a dental school hospital in Tokyo, Japan (n = 93, 72%). Participants were asked to complete an 11-item questionnaire assessing demographic variables and smoking history, provision of smoking cessation advice or care, attitudes about smoking cessation, and perceived barrier(s) to smoking cessation care. Eighteen percent of participants reported being current smokers and 15% reported being ex-smokers, with higher smoking rates reported by dentists compared with other health professionals (p = 0.0199). While recognizing the importance of asking patients about their smoking status, actual provision of smoking cessation advice or care by participants was relatively insufficient. Interventions such as 'assess willingness to make a quit attempt' and 'assist in quit attempt' were implemented for less than one-quarter of their patients who smoke. Non-smokers were more likely to acknowledge the need for increased provision in smoking cessation care by oral health professionals. 'Lack of knowledge and training' was identified as a central barrier to smoking cessation care, followed by 'few patients willing to quit'. CONCLUSIONS: A need for further promotion of smoking cessation activities by the health professionals was identified. The findings also suggest that dentists and dental hygienists, while perceiving a role in smoking care, do require training in the provision of smoking cessation care to hospital patients. In order to overcome the potential barriers, it is necessary to provide staff with appropriate training and create an atmosphere supportive of smoking cessation activities.