This study is connected to recent research that introduced achievement goal theory as a framework for research on teacher motivation. We aimed at investigating teachers' goals' indirect effects on their instructional practices through their reference norms. Drawing on a sample of 206 teachers, structural equation modeling revealed that mastery orientation was connected to more adaptive forms of reference norms and instruction, whereas less adaptive patterns were recorded for ability-approach orientation, ability-avoidance orientation, and work avoidance. Thus, school should not only focus on the enhancement of students' mastery goals but also on fostering teachers' mastery goals. (Contains 2 figures and 2 tables.)