This is the report of the APFIC regional workshop on "Mainstreaming fisheries co-management" held in Siem Reap, Cambodia from August 9-12, 2005 . The goal of the workshop was to provide a forum to learn from past experience and to promote devolved management of fisheries. Participants at the workshop had the opportunity to be exposed to a range of coastal and inland fisheries co-management interventions and the elaboration of approaches needed to make fisheries co-management a "mainstream" activity in developing countries. The objective of the workshop was to develop summary conclusions on the status of co-management in the region and provide some concrete recommendations for action towards mainstreaming fishery co-management in the Asia-Pacific region. The report contains the action plan and recommendations of the workshop. Many agencies (both governmental and non-governmental) are striving to improve the livelihoods of poor people that are dependent on aquatic resources by including these stakeholders in the planning and implementation of fisheries management. Many states have adopted decentralization as the way to implement future fisheries management, especially in developing countries, which often involves a partnership between government and the local communities, i.e. a co-management approach. The challenge is to find a way for co-management to become a mainstream practice of both government and non-government organizations and communities.