Difficulties in attracting student teachers have resulted in research focusing on student teachers' motives for studying to join the profession. Because previous findings are mixed, the first aim of this study was to explore motives for students to become teachers. A second aim was to explore the relationship between teachers' motives and their academic engagement and dropout rates at the end of their studies. A sample of 333 student teachers at a Swedish university completed a questionnaire measuring motives for becoming a teacher and their academic engagement. The best model of a confirmatory factor analyses defined three motivational factors as altruistic, intrinsic and extrinsic motives. A path analysis showed a negative significant relationship between the altruistic motive and dropout, mediated by academic engagement, whereas the relationships between intrinsic and extrinsic motives and academic engagement were not significant.