Background: One of the main causes of delay in diagnosis of oral cancer is lack of awareness about aetiologyand symptoms among the general population. The aim of this study was to assess the knowledge and practice ofpatients regarding oral cancer and their attitude towards tobacco cessation. Materials and Methods: This studywas carried out in Isfahan-Iran in 2014. A 29-item self-administrated questionnaire was designed and pilotedand distributed to patients attending dental clinics. Questions were focused on awareness about oral cancerrisk factors, signs and symptoms, places in the mouth which are more susceptible and attitude toward tobaccocessation. Chi-square, T-test, ANOVA and logistic regression tests were used for statistical analysis. Results: Atotal of 546 valid completed questionnaires were obtained. The mean knowledge score of patients was 4.1(±2.7)out of 13. Some 80% of patients did not know about early manifestations of oral cancer. Only 18% knew the mostlikely sites of oral cancer. Only 43.1% and 65.2% of patients reported alcohol and tobacco consumption as themain risk factors but they had a fair knowledge about other risk factors. There was no significant difference inKnowledge level between patients regarding their sex, educational levels and age. Most patents (90%) expectedtheir dentists to warn them about the harmful effects of smoking and showed willingness to quit if recommended. Conclusions: Knowledge about oral cancer was found to be quite low. It seems necessary to increase the levelof public awareness using educational programs with cooperation of dentists in tobacco cessation programs.