Background and Objectives: This study evaluated the associations between the characteristics of high school students and irregular breakfast consumption and explored the association with knowledge regarding diet and dietary education in a community in Japan. Methods and Study Design: A cross-sectional survey using a selfadministered questionnaire was conducted in 2007 among all the high school students in the second grade in Imari, Saga. Data for 318 male and 292 female students were analyzed. Irregular breakfast consumption was defined as consuming breakfast three times or less in a week. The associations between the characteristics of students and irregular breakfast consumption were assessed using logistic regression with adjustments for sex and school. Results: Among male students, a strong association between the consumption of juice or pop and irregular breakfast consumption was observed (OR comparing “≥2 servings” vs “rarely”=8.97, 95% CI=2.99–26.9). The associations with wake times and bed times were strong among male students, and the association with regular bowel movements was strong among female students. Students who had knowledge of regional agricultural and livestock products were more likely to consume breakfast regularly, and this association was significant among female students (OR=2.89, 95% CI=1.23–6.82). Significant associations were also observed with the consumption of snacks, and traditional greeting before meals. Conclusions: Several characteristics, including specific knowledge, were associated with the irregular consumption of breakfast. The results are of interest to policy makers, nutrition specialists, and educators working to enhance regular breakfast consumption among students.