This paper outlines each aspect of coordination as it relates to the responses made by various organizations in the disaster-affected areas. It is a synthesis of the presentations and discussions pertaining to coordination during the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO), in Phuket, Thailand, 04-06 May 2005. Coordination is defined, and two important questions are answered: (1) What coordination was done well?; and (2) What coordination could have been done better?