The Southern Economic Corridor (SEC), one of the priority economic corridors under the Greater Mekong Subregion (GMS) Economic Cooperation Program, was designated as a GMS flagship initiative in 2002. Efforts have been taken since then, but these were pursued mainly on a project-by-project basis. A series of consultations were conducted to initiate a holistic approach to the development of SEC. The strategy and action plan is the product of these and subsequent consultations with government officials, representatives of the private sector, and other stakeholders in these countries.Besides providing a vision and framework for developing SEC, this strategy and action plan is aimed at improving coordination, ensuring effective implementation, and helping the mobilization of resources and the broadening of support for SEC development. The second GMS Economic Corridors Forum, held in Phnom Penh, Cambodia on 17 September 2009, discussed and generally agreed with the directions set forth in this strategy and action plan.