The study is the first report of cultivable bacteria present in the close vicinity of hibernating bats. Samples were collected in January 2016 in one location outside the hibernation site and in five locations underground. Samples were incubated at 7 and 37 °C. Bacteria were identified based on phenotypic tests and 16S rRNA gene analysis. Air samples collected inside of underground sites contained more propagules of bacteria (from 232 28.3 to 1189 124.7 bacterial colony-forming units per m 3 of air) than outdoor air samples (42 12.2). In total, eight species of airborne bacteria belonging to three phyla and three orders were cultured from the samples. More species of airborne bacteria, eight, were isolated from the indoor underground air samples than from the outdoor air, two, especially in close vicinity to hibernating bats. Generally, Actinobacteria dominated in this study. Paeniglutamicibacter psychrophenolicus was isolated most frequently from samples incubated at 7 °C, and Micrococcus luteus from samples incubated at 37 °C. Additionally, the study was supplemented by detailed phenotypic and physiological characteristics of airborne bacteria obtained in the Nietoperek bat reserve.