This digest defines the concept of teacher leadership and examines the impact of teacher leadership on student achievement and equity within the schools. Most researchers agree that teacher leaders demonstrate expertise in their instruction and share that knowledge with colleagues; are consistently on a professional learning curve; practice reflection; engage in continuous action research; collaborate with peers, parents, and communities; become socially aware and politically involved; mentor new teachers; become more involved in preparing pre-service teachers; and are risk-takers who participate in school decisions. The ultimate measure of teacher leaders' contributions is the impact on student academic achievement. While some studies demonstrate no evidence supporting a relationship between teacher leadership and student achievement, others suggest that the bureaucracy of schools and systems, as well as the attitudes of educational policymakers, stifles the possibilities for teacher leaders to be effective as change agents. Some research suggests that unless issues of power, race, and class are addressed in school communities, the achievement levels of minority students will not be affected by teacher empowerment, noting that teacher leaders must learn to challenge the intellectual structures, definitions, and assumptions about people of color in Eurocentric institutions. (Contains 28 references.) (SM)