The evolution of rabies viruses of predominantly European origin was studied by comparing nucleotide sequences of the nucleoprotein and glycoprotein genes, and by typing isolates using RFLP. Phylogenetic analysis of the gene sequence data revealed a number of distinct groups, each associated with a particular geographical area. Such a pattern suggests that rabies virus has spread westwards and southwards across Europe during this century, but that physical barriers such as the Vistula river in Poland have enabled localized evolution. During this dispersal process, two species jumps took place - one into red foxes and another into raccoon dogs, although it is unclear whether virus strains are preferentially adapted to particular animal species or whether ecological forces explain the occurrence of the phylogenetic groups.