Using an institutionalist approach as the main framework, this research examines the evolution of Vietnamese agricultural cooperatives over the last six decades through four distinct phases - the voluntary collectivization period of 1954-1975, the compulsory collectivization period of 1975-1981, the de-collectivization period of 1981-1997 and the neo-collectivization period since 1997. Based on two case studies, this research examines the role of the Vietnamese government in the development of Vietnamese agricultural cooperatives. It argues that a stable legal environment and appropriate government support are extremely important for the successful development of cooperatives. In terms of theoretical contribution, the study calls for an integration of the notion of institutional dynamics into the current 'static' institutionalism and emphasizes the need to analyse institutions' influences at central, local and organizational levels to understand the formation and development of organizations. It also offers some policy implications that are relevant to the development of cooperatives in other economies.