The rapid development of aquaculture sector has contributed significantly to the Vietnam's economy. However, it also caused negative impacts to the environment as well as the degrees of the benefits received by aquaculture farmers. The Government of Vietnam promotes the bottom-up planning approach where farmers' participation is organized as an alternative for the top-down planning to ensure benefits to the farmers. This study focused on the issue of farmers' participation in an aquaculture development project. The main objectives were to describe the institutional framework for farmers' participation in the key project stages; to examine aspects and intensity of farmers' participation; to assess social, economic, institutional and environmental benefits and feedback of farmers from their participation; to analyze factors associating with farmers' participation and identify their problems, potential and needs. Recommendations were given to solicit farmers' participation in aquaculture development project, strengthen capacity of Commune Aquaculture Association, local and community leaders in organizing participatory aquaculture development activities more effectively.