Sixteen species of bats are reported from Margarita Island, Nueva Esparta, Venezuela. These include two species of emballonurids, one noctilionid, two mormoopids, nine phyllostomatids, one vespertilionid, and one molossid. Accounts including natural history and taxonomic comments are given for each species. The chiropteran fauna of Margarita Island is compared with the bat faunas of the adjacent Venezuelan mainland and islands off the northern coast of South America, including Trinidad and other Antillean islands. It is concluded that the chiropteran fauna of Margarita Island represents an attenuated mainland fauna.