The genome of a papillomavirus isolated from a cutaneous lesion on the head of an African grey parrot (Psittacus erithacus timneh) was cloned into pBR322, and a restriction map was prepared. Several short portions of the DNA were sequenced allowing the genome to be aligned with HPV-la. In Southern blot hybridizations, under conditions of low and medium stringency (Tm-40 and -33 degrees), but not at a higher stringency, this viral DNA annealed weakly with only 1 of 17 mammalian papillomavirus genomes tested. Furthermore, PePV DNA hybridized with the DNA from the European chaffinch only at low stringency, indicating that it represents a unique avian papillomavirus.