Sexual education is defined as informing individuals about sexuality, starting in the family and continuing at school. With this research, it is aimed to reveal the thoughts of high school students on sexual education. The study group of the study consists of 432 students selected by the stratified purposive sampling method, who continue at high schools in Dargecit district of Mardin Province in the Southeastern Anatolia Region. The data is collected via "Sexual Education Screening Form" prepared by the researchers in line with the literature in order to determine the demographic characteristics and thoughts of the students about sexual education. In the analysis of the data, utilizing the SPSS 20.0 statistical package program, the x(2) test was used to examine the number, percentage and difference. Research findings indicate that 53.7% of the participants did not have a romantic relationship, 74.5% did not receive sexual education, 31.9% received their sexual information from their friends, 36.6% talked with their friends on sexual matters, 58.3% needed sexual education, 50.9% of them do not want to take a course about sexual education / sexual health, 47.7% of them want to be taught by healthcare professionals, 47% of them want to be given sexual education in high school, 29.6% of them have knowledge about sexually transmitted diseases, 53.7% of them do not need information about sexually transmitted diseases. As a result, it is seen that students' knowledge about sexual education is insufficient and they need education. In our country, the number of studies conducted on this subject is low and the measurement tools that can be used in studies on this subject are insufficient. Therefore, the results of the researches reflect the characteristics of the sample groups. Research findings have been discussed in line with the related literature.