Low pathogenic avian influenza virus (LPAI) subtype H9N2 in poultry has occurredin many countries since the mid-1990s. Outbreaks due to H9N2 have occurred inKorea, Germany, Italy, Ireland, South Africa and the USA. Most recently, H9N2infections have been reported in several Asian countries, the Middle East andAfrica, causing widespread outbreaks in commercial chickens. In these countries,vaccine has been distributed with the aim of controlling the disease. However,H9N2 infections have become endemic in commercial poultry in a significantnumber of countries. This review is aimed to shed light on the current situationof the LPAI world-wide.