The avian paramyxoviruses consist of nine antigenic serotype. The Newcastle disease virus belongs to serotype-1 and is well characterized among all avian paramyxoviruses. Very little is known about avian paramyxovirus serotypes 2 through 9. Avian paramyxovirus serotype-3 (APMV-3) has been isolated from chickens and turkeys in different parts of the world. The pathogenicity of this virus varies from conjunctivitis, enteritis to signs of central nervous system disease. The detailed molecular, pathological and epidemiological characteristics of APMV-3 are not known. We have analyzed the growth characteristics of APMV-3 in different cell lines and chicken embryos. The pathogenicity studies of this virus in embryonated chicken eggs showed hemorrhages and mortality. Furthermore, virus infection in chickens and turkeys of different age groups showed virus replications in different organs. Complete genome sequence of APMV-3 strains PKT/Netherland/449/75 and turkey/Wisconsin/68 revealed unusually long trailer region, which is largest among all other avian paramyxovirus till date. Work is underway to develop a reverse genetics system for this virus, which will facilitate development of vaccine against this disease.