This study was carried out to measure the pathogenesis and molecular identity of an isolated Newcastle disease virus in a broiler farm with more than 85% mortality. Samples (swabs and tissue from the air sac, proventriculus, lung, trachea, and kidney) from broiler chickens were collected having difficulty breathing, depression, nasal discharge, and haemorrhage spots in the gastrointestinal tract. The extracted RNA was used in Real-Time PCR for NDV diagnosis. Specific primer for the partial Fusion gene amplification was used in conventional PCR, and the product was sequenced. In the results, there was clear heavy bleeding in the proventriculus and massive haemorrhagic dots in the gizzard and small intestines. The Real-Time PCR was successful in detecting the viral RNA, and the primer set was specific for partial F gene amplification in the conventional PCR. The nucleotide sequence of the NDV isolate was 20.1%–21.3% variable with all three vaccines used in the area, and it’s named Duhok/Iraq/2023 in the GenBank (Accession number: PQ368580). Further, this sequence shared 98.3% sequence identity with Class II and its sub-genotype VII.1.1. This study reveals the weakness behind the vaccination program against circulated NDV, and further studies are needed for evaluating the available or new vaccines against this disease.