This document outlines the background, objectives, contexts and deliverables of the highly pathogenic avian influenza (HPAI) project in the Mekong region, SE Asia. The first highly pathogenic avian influenza (HPAI) H5N1 strain emerged in 1996 when it was identified in geese in Guangdong Province in southern China. It then caused disease in Hong Kong SAR where poultry and humans were affected in 1997, poultry only in 2001 and early 2002 and poultry and captive wild birds in 2002‐03. From 2003 onwards the disease spread widely, initially through East and Southeast Asia in 2003‐04 and then into Mongolia, southern Russia, the Middle East and to Europe, Africa and South Asia in 2005‐06, with outbreaks recurring in various countries in 2007.