Recent research has confirmed both the importance of teachers in producing student achievement growth and in the variability across teachers in the ability to do that. Such findings raise the stakes on our ability to identify effective teachers and teaching practices. This paper combines information from classroom-based observations and measures of teachers’ ability to improve student achievement as a step toward addressing these challenges. We find that classroom based measures of teaching effectiveness are related in substantial ways to student achievement growth. Our results point to the promise of teacher evaluation systems that would use information from both classroom observations and student test scores to identify effective teachers. Our results also offer information on the types of practices that are most effective at raising achievement.