Nyctalus noctula and Barbastella barbastellus were first reported from Ireland in 1997, however these reports were based solely on echolocation call data. Since then, neither species have been reported again or confirmed as a resident species in Ireland. In this study the status of these two species in Ireland was assessed. For B. barbastellus, the woodlands in the area where it was previously reported from, in the Lough Derg region, were surveyed by walked transects using Pettersson D1000X bat detectors and through passive monitoring using the SD1 Anabat detector and the Pettersson D1000X over three nights. Out of 1011 recordings, no calls of B. barbastellus were encountered. For N. noctula, 98 Nyctalus sp. calls recorded from five squares (30 km²) on the east coast of Ireland, during a car based monitoring scheme were analysed (peak frequency and call duration). These were compared to 220 reference calls of N. leisleri from Dartry and Phoenix Park, County Dublin, Ireland and published data on N. leisleri and N. noctula calls from Britain. All Irish calls recorded from Dartry Park, Phoenix Park and the car transect squares fell within the known parameters range of N. leisleri but also overlapped with the higher frequency and shortest duration calls of N. noctula. However, no Irish calls overlapped with the lower frequency range and longest call duration of N. noctula, indicating that this latter species was probably not recorded in the Irish dataset. The results of this study are discussed in relation to the difficulty of reporting a bat species presence based on echolocation calls alone and the suitability of Ireland for both species.