Between 1958-2000, 3,148 records of hibernating bats were made in a natural limestone cave, 92 % of them concerning Rhinolophus hipposideros. Other species included Myotis myotis, M. mystacinus, M. brandtii, M. emarginatus, M. nattereri, M. daubentonii, Plecotus auritus, P. austriacus and Myotis blythii (which was not recorded after 1973). The abundance of R. hipposideros (and of all bats combined) decreased between 1958-1963, probably due to the impact of mark-recapture work, and between 1970-1974 due to the devastation of the cave. After the cave was put under protection and the marking of bats was stopped, the hibernating assemblage recovered so that, between 1984-2000, numbers of bats showed significant increases resulting in numbers more than twice those at the beginning of the monitoring period. Between 1991-2000, 517 bats were netted and banded from spring until autumn in front of the cave. Nettings of species not found in winter (Myotis bechsteinii, Eptesicus serotinus, Vespertilio murinus, Nyctalus noctula and Barbastella barbastellus) increased the total number of species to 15. In N. noctula and V. murinus echolocation signals were also detected and, in the latter a display flight with mating calls was recorded. Samples of netted bats were compared with samples of bats observed in the same winter, and significant differences were found in species composition, diversity and in the dominance values of individual species. It is suggested that considerable numbers of bats other than R. hipposideros occur at the locality in winter, but have remained undetected due to their hidden hibernation. We analysed 1,038 individuals marked at Turold and 237 recaptured, plus 10 of bats marked elsewhere and recaptured at Turold. The longest movement recorded (66 km) was in a female M. blythii, the highest age (19.5 years) was in a male R. hipposideros.