School transitions are important phases in students' educational experiences. The current study aimed to explore the trajectories of academic and social motivation across the transition from elementary to middle school. Participants (N = 415) were sampled from six elementary schools; 55% transitioned after sixth grade (transition) and 45% remained at the same school (no-transition). The students reported academic and social goals and perceived teacher goal emphasis at four time points over two successive years. A growth curve analysis revealed that students who transitioned reported a greater decline in mastery goals and an increase in performance-approach goals. Students from no-transition schools reported higher initial levels for all social goals, with a steeper decline in seventh grade. Perceived teacher goal emphasis was associated with social development goals over time. Practitioners should be aware that school transitions may influence academic motivation but may not similarly influence social motivation.