The purpose of this paper is to provide a conceptual framework that can be used by agricultural leaders, administrators, policy makers, and seed program managers to (1) understand key factors affecting seed system development; and (2) compare organizational and institutional strategies for increasing seed system effectiveness. A literature review of recent studies on seed system development in Sub-Saharan Africa (SSA) was undertaken to achieve these objectives. The studies reviewed included published and unpublished reports, monographs, and case studies.