It is critical to integrate, or “mainstream” thinking about climate change into development strategies, plans and programmes. This is especially true when pursuing goals that are most likely to be affected by the impacts of climate change, such as greater access to safe drinking water, healthy ecosystems or foodsecurity. This Toolkit offers practical, “how to” guidance for integrating climate change adaptation into the design, implementation, monitoring and evaluation of development projects. Its step-by-step structure helps users build climate-resilient projects with sustainable impacts. It also includes checklists to ensure that development activities don’t increase people’s vulnerability to climate change. The Toolkit provides guidance and recommended tools for all stages of the project cycle, as well as tools, resources and practical examples from CARE projects around the world. Water resource management and agriculture projects are specifically highlighted, as they were targeted in the early tests of the Toolkit. This is seen as a ‘living’ document or resource; therefore, feedback is welcome on its structure, content and overall utility from users. The authors plan to update the Toolkit periodically as they receive feedback and continue to learn more about the process of integrating adaptation into development projects.