This report provides an outline of protected areas and biodiversity in the Lower Mekong Basin. The analysis contains an overview of threats to protected areas from climate change, as well as non-climate threats such as land concessions, infrastructure development, illegal activities, and agriculture. The threats posed by climate change to protected areas are then reviewed, followed by a series of case studies of climate change impacts, vulnerabilities, and adaptation options in four protected areas: 1) Nong Bong Kai Non Hunting Area – Thailand; 2) Nakai Nam Theun - Lao PDR; 3) Phnom Prich Wildlife Sanctuary - Cambodia; and 4) U Minh Thuong National Park – Vietnam. This report is part of the wider Climate Change Impact and Adaptation Study of the USAID Mekong ARCC project.