This paper examines district leaders' theories about teacher learning and change, identifying and elaborating three perspectives--quasi-behaviorist, situated, and quasi-cognitive--based on a study of nine school districts. The quasi-behaviorist perspective on teacher learning dominated among the district leaders in the study. To account for the prominence of the quasi-behaviorist perspective, the author considers how district leaders' work is structured in ways that support a quasi-behaviorist perspective. Specifically, the author considers the manner in which relations between district leaders and teachers are constituted in interaction with state and local policy environments to support a quasi-behaviorist view of teacher learning and instructional change. Based on the analyses of the data (collected through interviews) the author argues that changing the training paradigm that dominates school districts' approach to professional development will necessitate challenging district leaders' theories about teacher learning. Specifically, unless reformers create opportunities for district leaders to develop alternative conceptions of teacher learning and change (that is, conceptions that are different from the quasi-behaviorist perspective), the training paradigm is likely to persist. (Contains the interview instrument in an appendix, tables that describe characteristics of the school districts and district leaders' theories of teacher learning, and 43 references.) (Author)