<p>Background: As cancer has been a leading cause of death in Japan since 1981, the development of a cancer education curriculum for school children is a critical issue. Here, we clarified the level of cancer awareness among Japanese students.</p><p>Methods: We conducted a nationwide mail questionnaire survey with random sampling proportional to the student population and types of school in each prefecture. Questionnaires were delivered to 213 elementary schools, 222 junior high schools, and 208 high schools. Respondents in this survey included the fifth grade of elementary school (10 or 11 years old), second grade (13 or 14 years old) of junior high school, and second grade of high school (＞16 years old) in Japan.</p><p>Results: The response rate among schools was 44.1％ (94 of 213) for elementary schools, 46.4％ (103 of 222) for junior high, schools and 55.8％ (116 of 208) for high schools. Valid responses were obtained from 2,213 elementary school students, 2,960 junior high school students, and 3,703 high school students. The response rate for “fearful” about cancer was 72.1％ for elementary school students, 66.3％ for junior high school students, and 69.2％ for high school students. The response rate for “I think I could recover from cancer with medical treatment” was 25.8％ for elementary school students, 23.9％ for junior high school students, and 22.8％ for high school students. Regarding the question “Do you think you will develop cancer？”, the response rate for “I don't know” was the highest of potential responses, at 42.6％ for elementary school students, 37.2％ for junior high school students, and 30.2％ for high school students. As respondent age increased, so did the proportion who answered “I think I will have cancer in the future, ” as follows: elementary school students (8.5％), junior high school students (13.2％), and high school students (19.6％). In contrast, the response rate decreased with increasing age for “I think cancer is preventable, ” as follows: elementary school students (57.4％), junior high school students (47.9％), and high school students (43.3％) A similar decreasing trend was also observed for “I want to undergo cancer screening when I reach the suitable age, ” as follows: elementary school students (77.9％), of junior high school students (68.3％), and high school students (67.4％).</p><p>Conclusions: As respondent age increased, changes of cancer awareness were observed. However, it is hard to say that these results were enough to keep or improve their health behavior in the future.</p>