This article examines the negotiations on the 1995 Mekong Agreement, signed by Cambodia, Laos, Thailand and Vietnam. A “negotiation analysis” approach is used based on understanding interests and “disagree” alternatives. The article is based on interviews with the author with about 25 principals in the negotiations. Thailand and Vietnam, regional powers, wanted to establish cordial relations after the Cold War and needed the agreement to stem conflicts and promote cooperation on water resources. Laos and Cambodia were motivated to reach an agreement to purchase aid. China`s planned hydroelectric reservoirs could increase the flow of the dry season, allowing lower Mekong countries to share future increases in dry season flow. Support for UNDP negotiations was necessary to overcome a legacy of mistrust. Key articles of the agreement deal with the maintenance of dry season flows, notification procedures and a watershed development plan. Acquire immediate access (pdf download and unlimited online access):. . .