The doline Buraco das Araras is a peculiar environment and important destiny for ecotourism in the Serra da Bodoquena region, Mato Grosso do Sul, Brazil. Here we describe the bat fauna of the doline and surrounding areas, and report its use as dayroost by the bat Nyctinomops laticaudatus. Bats were mist-netted during two field expeditions, in November 2007 and January 2008. We captured 153 individuals of 10 species, mainly N. laticaudatus (n = 90) and Artibeus planirostris (n = 28). This is the first record of N. laticaudatus in the Serra da Bodoquena region; it was captured only in January when leaving the doline in dense flocks at dusk. Phyllostomus hastatus, Micronycteris sanborni, and Molossops temminckii are also new records for the Serra da Bodoquena region. Three individuals - A. planirostris, Carollia perspicillata and Glossophaga soricina - tagged in November were recaptured in January, indicating that these species are residents. The doline and bordering vegetation appear to be important sources of shelter and food for bat fauna maintenance.