Highly pathogenic avian influenza (HPAI) represents a threat to poultry industries worldwide and to people's livelihoods, and a potential threat to human health. The international community has a vested interest in minimizing the spread of this disease. Countries may be under threat of introduction of HPAI through unregulated poultry trade and marketing practices and, on rare occasions, exposure of poultry to wild birds, especially waterfowl. FAO and the World Organisation for Animal Health have prepared the first edition of this manual to help national animal health authorities and other stakeholders prepare for a possible incursion of HPAI, detect disease as soon as possible and respond as rapidly as possible to contain the disease. This second edition reflects lessons learned and provides additional details. This manual is an invaluable source of useful information for anyone involved in poultry-keeping and animal health practices.