Technical Abstract: Avian influenza (AI) and Newcastle disease (ND) are caused by type A orthomyxovirus and type 1 paramyxovirus, respectively. Both low and high virulent forms of these diseases occur. The high virulent forms of AI and ND impact international trade as does some forms of low pathogenicity (LP) AI. The high virulent forms of ND have been reported more frequently than highly pathogenic (HP) AI. Clinical features of AI and ND are not diagnostic and require virus isolation and identification to make a definitive diagnosis. Some strains of AI and ND viruses have shown the ability to change from low to high virulence which complicates control programs. Dealing with ND and AI has focused on prevention, control and eradication depending of the virus strain and country. Infections in humans by AI and ND viruses have been reported.