The objective of this study is to analyze the strengths, weaknesses, sustainability, and impact of the tsunami response in Sri Lanka and Indonesia 10 years later. A cross cutting theme of this study is the assessment of whether communities are now better prepared to respond to and cope with disaster. Three key lessons for the future of humanitarian response are highlighted: Lesson 1: Participation is the cornerstone of humanitarian response and recovery; Lesson 2: Partnership as a prerequisite for long-term change; Lesson 3: Creating momentum for risk reduction.