Animal viruses are tiny packages of protein and nucleic acid. Avian paramyxovirus type 1 (APMV-1) causes Newcastle disease (ND) in chicken.ND is one of the highly pathogenic viral diseases of avian species. ND is economically significant because of mortality and morbidity associated with it. APMV-1 belongs to the family Paramyxoviridae and the genus Avulavirus.Recent advances in recombinant DNA techniques have brought forward to an era of new vaccine technology in modern medicine. One attractive strategy is the application of reverse genetics to make recombinant APMV (rAPMV). rAPMVcan deliver protective antigens of pathogens in host and evoke a protective immune response. The rAPMV vaccine offers a pertinent choice for the construction of live attenuated vaccine due to its minimum recombination frequency, modular nature of transcription and lack of DNA phase during its replication. APMV is also explored widely in the field of cancer biology due to its property of replicating selectively in tumor cells. In the recent years, the reverse genetics technology allowed to generate rAPMV having high tumor suppressor property. By understanding APMV molecular biology, it is feasible to develop gene-modified recombinant vaccines possessing better safety and immunity for both animals and humans.