This study constitutes the first record of parasitism and associations between bat flies ectoparasite of the Streblidae family and bats (Chiroptera: Phyllostomidae) in the São Francisco Forest State Park (SFFSP). The bats were captured using mist nets set up at various points along the park’s visitor trail. Following collection, the bats were inspected for ectoparasites, which when found were collected with metal tweezers and stored in vials with 70% alcohol to be identified later. The captured bats were subjected to morphometrics so that the information obtained could help identify which bat species was the host of the ectoparasite collected and then they were released. A total of 36 dipterans from the Streblidae family belonging to six species from four genera: Aspidoptera falcata Wenzel, 1976; Aspidoptera phyllostomatis (Perty, 1833); Megistopoda aranea (Coquillett, 1899); Megistopoda proxima (Séguy, 1926); Paratrichobius longicrus (Miranda Ribeiro, 1907) and Trichobius. joblingi Wenzel, 1966, infesting phyllostomids of four species: Artibeus lituratus (Olfers, 1818); Artibeus planirostris (Spix, 1823); Carollia perspicillata (Linneaus, 1758) and Sturnira lilium (E. Geoffroy, 1810). The most abundant species were Trichobius joblingi (38.89%) and Aspidoptera phyllostomatis (27.78%).