The 100th anniversary of the International City/County Management Association provides an excellent point to review and assess research on the performance of the council-manager form of government. The development of the council-manager form arguably has been the most important innovation in American local government over the last century, yet its impact on the performance of municipal governments is not well understood. This article reviews and assesses the empirical evidence for 10 propositions that council-manager governments perform better than mayor-council governments. This evidence indicates that although progress has been made on demonstrating differences in representation and functionality, the proposition that council-manager governments are better managed than mayor-council governments has yet to be seriously engaged in this literature. Filling this critical gap requires progress in two areas: the development of theory to explain why council-manager governments are better-managed organizations and the production of evidence assessing the major propositions of this theory.