It is well known that smoking, chewing tobacco, and alcohol play a significant role in the etiology of oral cancer. Although this is common knowledge in the medical community, it appears that patients are not aware of this association. We performed a prospective study on all patients newly diagnosed with oral cancer and a control group without any head and neck cancer. Patients completed a questionnaire assessing their awareness of these causative factors. Other parameters measured as possible influences of patient perception included patient age, sex, smoking status, education level, occupation, and place of residence. Patients were also questioned about their knowledge of the causes of lung cancer to allow for comparison. A total of 134 patients were questioned, with 22 of the patients assigned to the oral cancer group and the second group being comprised of 112 patients without head and neck cancer. Only 20 patients (14.9%) were aware of the causative factors of oral cancer. There was no significant difference in the knowledge of causation when comparing the cancer and control group. The patient age, sex, smoking status, or place of residence did not affect their knowledge of the causes of oral cancer. There was a highly significant difference between patients of different education levels and occupations, with the more educated and higher level occupations being better informed about the causes of oral cancer. In contrast, the majority of patients were aware of smoking as a causative factor in the development of lung cancer. The results from this study demonstrate a serious lack of knowledge in the general population of known causes of oral cancer. The relevant issues are discussed and recommendations are made.