This paper describes the basic elements of Mastery Learning, as outlined by Benjamin S. Bloom, and Mastery Teaching, as outlined by Madeline C. Hunter. It shows that while these two instructional approaches are clearly distinct, they can actually serve as complements to one another. In addition, each can bring added strength to the other such that when used in combination, results are likely to be better than either can achieve alone. Implications for staff development and instructional improvement programs in general are also discussed. (Author)