The Vam Ray coast, Kien Giang Province, Vietnam, was seriously eroded by 2008. In May 2009, a demonstration project was established which achieved a high survival rate of transplanted mangroves and sea mud accumulation. This study used participatory action research methods (literature review, semi-structured interviews, field visits, and peer debriefing) to evaluate the project outcomes. Despite the project being generally very successful, its implementation and results were inadequately documented by agencies involved due in large part to insufficient local involvement during the reporting process, even though the local community was fully involved in the project planning and implementation. Inadequate documentation has led to mistakes being made when attempts have been made to replicate the project elsewhere, and incomplete findings have been incorporated into mangrove management plans at the provincial and regional levels. Using the community knowledge from the time of the project implementation and since, we detail the successes and problems encountered to provide more complete reporting, to assist transferability of the methods to other eroding muddy coasts in Vietnam and potentially elsewhere.