Introduction: Oral cancer (OC) is a disease with a high mortality rate due to its late recognition. Since the oral cavity is easily accessible for visual inspection, enabling early diagnosis, the education of healthcare workers about preventive oral examinations is critical. This research aimed to assess the level of participants’ OC knowledge, as well as to raise awareness about this diagnosis. Materials and methods: The research was conducted as an online survey among students of dental medicine, students of medicine, doctors of dental medicine and doctors of medicine. The questionnaire was designed solely for the purpose of this study and consisted of 29 questions. The first part of the questionnaire consisted of general questions about the participants, whereas the questions in the second part addressed their knowledge and attitudes towards OC. Results: The surveyed population comprised of 140 dental students, 105 medical students, 159 doctors of dental medicine and 100 medical doctors. The level of knowledge about OC among the participants is not yet satisfactory. The group of dental medicine students scored highest, while medical doctors showed the weakest knowledge. Conclusion: Additional education about OC for doctors of dental medicine and medical doctors is needed. This step will improve prevention and increase chances for early detection.