Background: The effectiveness of smoking cessation intervention by dentists has not been conclusively established. This study aimed to investigate whether the inclusion of graphic health warning pictures (including mouth and throat cancer) as part of the Australian National Tobacco Campaign strategy would elicit measurably increased demand for smoking cessation advice in dental practices. Methods: A cross-sectional survey of private dental practices in New South Wales, Australia. Separate questionnaires were answered by dentists and patients from their practice. Questions comprised smoking practices and attitudes toward smoking cessation activities in dental practice. Results: The majority of dentists (85.7 per cent; n = 29) and dental patients (92.4 per cent; n = 800) recalled seeing the graphic health warnings, with mouth and throat cancer the most commonly observed. Television was the main medium. Nineteen per cent of dental patients (n = 152) reported themselves as current smokers. Half of them were planning to quit within six months (49.7 per cent) and agreed that graphic health warnings made them more likely to quit (47.7 per cent). Dentists showed positive attitudes toward cessation activities but believed many patients lacked motivation to quit smoking; a perception that was seen to be the main barrier in offering smoking cessation advice. Forty per cent of smokers would try to quit if asked by their dentists, but only 28.4 per cent preferred a dentist for cessation advice. In general, dentists found no change in demand for smoking cessation advice since the launch of the National Tobacco Campaign in 2006. Conclusions: Health warning pictures seemed to increase the patients' awareness and intention to quit smoking, however it did not appear to generate more demand for smoking cessation advice from their dentists. Dentists had low expectations about their patients' motivation to stop smoking.