This Synthesis Report is the outcome of an international collaborative process involving over 40 humanitarian and development cooperation agencies. Individuals involved have come primarily from the evaluation departments of UN agencies, multi- and bilateral donors, as well as non-governmental organisations, the Red Cross Movement and a number of research groups. This synthesis is based on these five thematic studies, each undertaken by one or more independent evaluation team/s. The evaluations involved in-depth country case-studies, beneficiary surveys and extensive consultations with stakeholders. The report also benefits from a wealth of secondary sources produced on the tsunami response.