The goals of this handbook are a) to present a comprehensive understanding of what mainstreaming climate change adaptation means; b) to provide detailed guidance on how mainstreaming climate change adaptation can be put into practice. It provides: methodology; practical tools; case studies; guidance and relevant information on how to assess project and program vulnerability to climate variability and change; and how to design and adapt projects so that they are more resilient to a range of climate change scenarios. Primarily designed for CARE in Vietnam, but may prove useful to other development NGOs and project partners.