Purpose: The purpose of this paper is to examine how US school leaders make sense of external mandates, and the way in which their understanding of state and district accountability policies affects their work. It is posited that school leaders' responses to external accountability are likely to reflect a complex interaction between their perception of the accountability policies, the state and district contexts in which those policies are situated and their own leadership beliefs and practices. Design/methodology/approach: The authors use both principal and teacher survey data to explore the question of how perceptions of external policy are associated with instructional leadership behaviors. Cases of seven principals are employed to flesh out the findings from the survey analysis. Findings: It is concluded that external accountability policy may have a positive impact on instructional leadership--where they see those policies as aligned with their own values and preferences, and where they see their district leaders as supportive of school-driven accountability initiatives. In these cases, school leaders internalize the external accountability policies and shape them to the particular needs that they see as priorities in their own school. Where one or the other of these factors is weak or missing, on the other hand, leaders demonstrate more negative attitudes to external accountability and weaker instructional leadership. Originality/value: This analysis draws on a unique, large-scale data base and uses a mixed methods approach to answer the question. (Contains 4 tables, 2 figures and 10 notes.)