It can be said that Turkish society is not very interested in mythology, and therefore, they do not have much knowledge on this subject. However, this fact does not change the reality that the Turks have a rich mythological history and numerous narratives on this subject. Based on this idea, the aim of this study is to comparatively examine the knowledge levels of ninth and tenth grade high school students about Turkish and Roman-Greek mythology. The study is a quantitative study in which the descriptive research model is used. In the study, a questionnaire was used to determine the characters of Turkish and Roman-Greek mythology to collect data. Data were collected from a total of 117 ninth and tenth grade students in three different types of high schools in Erzincan. As a result of the study, it was seen that high school ninth and tenth grade students did not have much knowledge about Turkish and Roman-Greek mythology. It was concluded that the students knew Roman-Greek mythology more than Turkish mythology. In line with the results, various recommendations were developed.