Fossil bats are described from the karstic deposits of the Erkertshofen 1, Erkertshofen 2 and Petersbuch 2 sites in eastern Bavaria, southern Germany (MN 4). Fossils are discussed with regard to taxonomic, stratigraphic and palaeoecologic significance. The rich fossil material represents at least 12 different bat species belonging to Megadermatidae, Rhinolophidae and Vespertilionidae. The syntopic appearance of four different rhinolophids is demonstrated for the first time for the Neogene bat assemblages of Europe. The remains of Rhinolophidae and Vespertilionidae are the most numerous, of which the proportion of typically early Miocene species Rhinolophus aff. lemanensis, R. dehmi, Hanakia agadjaniani and Miostrellus cf. petersbuchensis are significant. However, there are also remains of R. cf. delphinensis, M. cf. noctuloides, Plecotus cf. atavus and H. aff. antiquus, which are characteristic of the younger middle Miocene faunas of Central Europe. Analysis of the composition of the bat fauna has allowed biostratigraphic correlation of the studied faunas to be estimated at a number of other early Miocene localities in Europe.