In the context of long-term screening for viruses on Western Palaearctic bats, we tested for the presence of adenovirus 1.392 oropharyngeal swabs and 325 stool samples taken from 27 bat species. Adenoviruses were detected in 12 species of the Vespertilionidae and the Rhinolophidae families. Fifty positive respiratory and 26 positive stool samples were studied. Phylogenetic analyses of partial hexon protein and partial DNA-dependent DNA polymerase genes, indicate all these bat adenoviruses belong to the genus Mastadenovirus but without constituting a monophyletic cluster. According to genetic identities, the new groups are distinct to the previously described Bat mastadenovirus A and B species, and contribute with potentially new members. Our data support that diversity of Bat mastadenovirus is host-dependent and increase the knowledge of potentially pathogenic virus from bats. For human concerns this knowledge is an important Public Health issue due to the active role of bats as viral reservoirs.