Carios vespertilionis Latreille, 1802 is a typical bat parasite, widely distributed in the Palearctic, Oriental and Afrotropical realms. Its localities were found throughout Poland, yet it is considerably more common in the south. Currently, 105 bats have been examined, collected in the period 1999–2017 from 27 localities in northern Poland; 102 C. vespertilionis larvae were noted in 6 bats of 3 species of the Pipistrellus genus, originating from 5 localities, of which all constitute new locality for the short-legged bat tick. Instances of C. vespertilionis larvae wintering in the hosts have been observed as well as occurrence of this parasite outside of bat breeding colonies.