The present study aims to determine the knowledge level of high school students regarding oral cancer. The present study included students from 20 high schools located in the city center of Kahramanmaras between 1 and 28 April 2015. The students were informed prior to the study and 2759 students who gave written consent were included in the study. The participants were administered a questionnaire that was prepared by the investigators. The questionnaire included 25 questions that were prepared using literature in order to establish the knowledge level of the students about oral cancer, and it was evaluated scoring one point to each question. There were 1711 (62.0 %) female students and 1048 (38.0 %) male students; the mean age was 16.01 +/- 1.09 years. The knowledge score of the male students was 7.48 +/- 5.15 and the knowledge score of the female students was 7.58 +/- 4.96. The knowledge score of the female and male participants was similar (p = 0.605). Of the students, 2107 (76.4 %) stated that they heard the expression of oral cancer before compared to 652 (23.6 %) students stating they did not. The study found that high school students had insufficient levels of knowledge about oral cancer. There was a general lack of knowledge about oral cancer and the risks among these students.