New Zealand has never experienced an outbreak of avian influenza, and the Ministry of Agriculture and Forestry has long been wary of the possibility of introducing high-pathogenicity avian influenza (HPAI) viruses in imported goods. Besides the potential threat posed to poultry, there are concerns that introduced viruses might have negative effects on already endangered native avian species. Under the framework of the World Trade Organization, the sanitary and phytosanitary (SPS) agreement requires member countries to base their sanitary measures for imported animal products on the Office International des Epizooties (OIE) standard or on a scientific assessment of risk. This paper presents the New Zealand experience with assessing the risk of avian influenza viruses in imported chicken meat and considers how the assessment of risk has changed in recent years as a result of the advances in understanding of the disease. The currently accepted view that low-pathogenicity avian influenza (LPAI) viruses are widespread and that they mutate to virulence after introduction into poultry has important implications concerning the appropriate definition for avian influenza viruses of regulatory concern and has possible implications concerning the significance of viruses present in this country.