This cross-sectional study aims to respond three research questions: (1) Do perceived teaching styles predict students' motivation, academic engagement, and disaffection? (2) Does students' motivation predict engagement and disaffection? (3) Does motivation mediate the influence of teaching styles in students' engagement and disaffection? A convenience sample of 409 social work undergraduates from Spain (80.9% females) completed a questionnaire with these constructs. Structural equation modeling analyses showed that perceived teaching styles directly only predicted students' autonomous and controlled motivation. These two modalities of motivation predicted engagement and disaffection and mediated the influence of teaching styles on engagement and disaffection. These findings highlight the need for interventions enhancing teachers' autonomy-support and structure and reducing control.