This document summarizes a study that examined the relationship between classroom structure, self-determined motivation, and engagement in elementary foreign language classes in Japan. The study hypothesized that (1) teachers' classroom structure would promote students' feelings of autonomy, competence, and relatedness, and (2) these psychological needs would mediate the influence of structure on students' emotional and behavioral engagement. Surveys and observations were used to analyze these relationships in 14 foreign language classes involving 396 fifth-year Japanese students. The results supported the hypotheses, showing that classroom structure positively predicted the three psychological needs and engagement.