The full-length genome of goose hemorrhagic polyomavirus (GHPV), the ethiologic agent of hemorrhagic nephritis and enteritis of geese, was cloned and sequenced. Transfection of the circular ds DNA with a size of 5256 bp and an organisation typical of polyomaviruses produced viral progeny in cultured goose cells. According to the splicing sites determined by RT-PCR, five open reading frames (ORFs) were found to encode putative proteins with significant similarities to large T antigen and small t antigen as well as VP1, VP2, and VP3 of other polyomaviruses. An additional ORF located in the 5' region of late mRNA, with a coding capacity for 169 amino acids, shows a low degree of homology to VP4 of avian polyomavirus (APV). The alignment of nucleotide sequences and amino acid sequences revealed a relatively close relationship between GHPV and APV. Therefore, grouping of this new polyomavirus into the proposed subgenus Avipolyomavirus is suggested.