The purposes of this study are (1) to clarify the importance of enhancing Japanese students' self-efficacy for healthy eating to help them to practice a healthy diet, and (2) to consider effective strategies for enhancing students' self-efficacy for healthy eating through nutrition education in Home Economics class. The research was carried out to examine the changes in and relationships between self-efficacy for healthy eating, knowledge about food and nutrition, cooking technique and eating behavior of Japanese senior high school students. Data were collected from second-year students in school A (68 male students and 113 female students) and third-year students in school B (117 male students and 122 female students). They completed a questionnaire before and after nutrition education in Home Economics class. Path analysis revealed that (1) the students' self-efficacy for healthy eating influenced their behavior about eating a healthy lunch, and (2) the students' knowledge about food and nutrition and cooking technique influenced their self-efficacy for healthy eating. Furthermore, it was found possible to enhance the students' self-efficacy for healthy eating through nutrition education in Home Economics class. The findings of this study suggest that teachers should help students to acquire skills to judge the nutritional balance of menus with basic knowledge about food and nutrition and to improve cooking technique for enhancing their self-efficacy for healthy eating and encouraging them to practice healthy eating.