This synthesis report is the outcome of an international collaborative process involving over 40 humanitarian and development cooperation agencies. This report synthesizes the five Tsunami Evaluation Coalition (TEC) thematicevaluation reports, their sub-studies and other materials relating to the Indian Ocean earthquake and tsunamis of 26 December 2004. The evaluations involved in-depth country case-studies, beneficiary surveys and extensive consultations with stakeholders. The report consists of three main parts: an introduction, sections on the disaster andresponse and conclusions and recommendations. It addresses, primarily, the initial phase of the international response, up to the first 11 months after the disaster. The report has two main aims: to improve the quality of natural disaster response policy and practice, and to account to both donor and affected-country populations. Four main recommendations emerge fromthis synthesis report. They are: 1) the international humanitariancommunity needs a fundamentalreorientation from supplying aid tosupporting and facilitatingcommunities’ own relief and recovery priorities, 2) all actors should strive to increasetheir disaster response capacities andimprove the linkages andcoherence between themselves andother actors in the internationaldisaster response system, includingthose from the affected countries themselves, 3) the international relief system shouldestablish an accreditation andcertification system to distinguishagencies that work to a professional standard in a particular sector, 4) all actors need to make the currentfunding system impartial, and moreefficient, flexible, transparent andbetter aligned with principles of good donorship.