Newcastle disease (ND) is an acute viral disease of domestic poultry and other bird species. ND is caused by viruses in the serotype Avian Paramyxovirus type 1 (APMV-1). It is a worldwide problem that ranges clinically from inapparent to a rapidly fatal condition, characterized by gastrointestinal, respiratory and/or nervous signs. The many ND virus strains vary widely in virulence and tissue tropism. Newcastle disease virus transmission between poultry occurs through fecal-oral route. Following replication of NDV in their respiratory and/or digestive tract, infected birds shed the virus through aerosol and/or droppings. The presence of virulent strains in poultry requires monitoring and control measures because the existence of the virus severely impacts commercial productivity and international trade in poultry and poultry products. Both attenuated live and inactivated vaccines are used to control the disease.