Documenting rare intrasexual interactions is crucial to improving our understanding of the social and sexual diversity of bats. Here, we present the first confirmed observations of same-sex mounting in Kuhl's pipistrelle (Pipistrellus kuhlii), as recorded during routine monitoring at the Austrian Bat Rehabilitation Centre. Two of the interactions involved adult male P. kuhlii, who maintained stable mounting postures and rhythmic pelvic thrusts for several minutes after initiating the interaction. A third, brief male-male mounting interaction was observed between Pipistrellus pygmeus and an adult Pipistrellus kuhlii. All interactions were calm, showing no aggression or avoidance behaviour. These observations emphasise the importance of recognising and documenting such rare behaviours in order to expand our knowledge of bat´s social and sexual diversity.