This paper examines the existing and potential roles of educational service agencies (ESAs) and their relationships with state education agencies (SEAs) and local education agencies (LEAs). Special attention is focused on urban school districts. The paper also critically analyzes these roles and relationships as they relate to dissemination functions, with particular emphasis on the role of the ESA in the Research and Development Exchange (RDx). The history of the ESA is outlined, and studies of the education service agency in Michigan, Pennsylvania, and other states are examined. These studies lead to specific recommendations regarding generally appropriate roles and functions. Roles and functions for the ESA in dissemination evolve from recent federal legislation focusing on research relative to educational change, broker/facilitator roles, nature of the educational enterprise, state and national dissemination agencies, and educational renewal and reform. A number of specific conclusions and recommendations relevant to the ESA and RDx are offered: no nationwide single-agency system or configuation for dissemination can adequately respond to all education needs; the professional community must support comprehensive research and development evaluation studies about regionalism; and the RDx configuration needs more client user input at all levels of planning, management, and stages of development. (Author/JM)