This quasi-experimental study examined the effects of a self-reflection intervention on college (college in this article refers to university-level education) students' positive thinking, learning motivation and self-regulation in Taiwan. One hundred and two college students were selected to participate in an 18-week intervention forming the experimental group (EG) which emphasized providing main lecture, role-play, self-reflection activity, group discussion and group work. Another 179 college students from two other courses were selected as a comparison group. This study showed that supportive, resourced discussion with peers and instructor, self-reflection activities and assignment as a facilitative agent improved the EG students' positive thinking, learning motivation and self-regulation. In addition, three structural equation models revealed that positive thinking had a strong and direct relation to Taiwanese college students' pretest learning motivation (ß = 0.85) and self-regulation (ß = 0.77); learning motivation had a strong and direct relation to students' pretest positive thinking (ß = 0.86) and self-regulation (ß = 0.81); and self-regulation had a strong and direct relation to students' pretest positive thinking (ß = 0.83) and learning motivation (ß = 0.86). Instructional implications and research recommendations are discussed.