Purpose/Objectives: The purpose of this study was to identify the aspects of the Theory of Planned Behavior with the greatest relevance to plate waste (PW) among elementary school children in Tokyo, Japan. Methods: A total of 111 fifth- and sixth-grade students at an elementary school in Tokyo, Japan responded to a self-report questionnaire. The questionnaire focused on the associations among attitudes, subjective norms, perceived behavioral control, and PW behavior. Differences based on gender, grade level, height, and weight were considered. Pearson's correlation coefficients (r) and multiple regression analyses were used to examine the factors contributing to PW. Results: Scores for attitudes toward PW were higher among girls ("p" less than 0.05). Perceived behavioral control ("r" = 0.535, "p" less than 0.001) was associated with PW. Perceived behavioral control had an impact on PW (standardized ß = 0.593, "p" less than 0.001, adjusted "R"superscript 2] = 0.332). Application to Child Nutrition Professionals: Although nutrition education directed at reducing PW in Japan has focused on attitudes, this study suggests that perceived behavioral control is also important for helping children reduce PW.