Bovine enteric noroviruses form a genogroup, III, distinct from the 2 human norovirus genogroups, I and II. Two genogroup III genotypes were suggested by partial genomic analyses. In the present study, analysis of the full-length genome sequence of Bo/Newbury2/76/UK and the more contemporary Newbury2-like virus, Bo/Dumfries/1994/UK, showed that both were 7311 nucleotides in length and had three open reading frames (ORFs), amino acids motifs typical of noroviruses, and 95% or greater amino acid identities to each other in all regions of their genome. Apart from the ORF1 NTPase region, their ORF1 regions had less than 90% identity to the genogroup III genotype 1 Bo/Jena/80/DE virus, confirming two genogroup III genotypes. A close antigenic relationship was demonstrated by ELISA between the genotype 2 viruses, which will allow their serological diagnosis.