Newcastle disease (ND) is one of the most devastating poultry diseases and can affect a broad range of avian species. Being a good animal model virus, and with the availability of reverse genetics, the pathobiology of ND virus (NDV) has been well studied. However, despite effective and safe vaccine availability, the disease is still endemic in many parts of the world, especially in developing and ND-endemic countries, mainly due to poor vaccine stability and accessibility. There are several aspects of NDV that still require future research, including a better classification system, molecular determinants of virulence, vaccines with sterile immunity and that effectively control virus shedding, and the interaction of NDV with its natural hosts. In this chapter, I detail our current understanding of the pathobiology of the virus, and discuss available control and disease management tools and resources.