This chapter outlines the considerations necessary in planning and conducting evaluations of teacher leadership programs. It contains a discussion of different definitions of evaluation, their underlying philosophies, and their importance for teacher leadership programs. Specific ideas for conducting teacher leadership program evaluations are presented. These included: evaluation of the delivery of professional development programs, effects on teacher leaders, effects on classrooms and students, effects within schools, and effects within districts and states. Suggestions include both qualitative and quantitative approaches, and examples are provided from existing teacher leadership programs. The Horizon Research Inc. forms for classroom and professional development observation are described in some detail. (Contains 27 references.) (Author/MVL)