The fauna and community ecology of percolation water was studied using monthly samples of 12 drips in the Medvedji rov in the cave Huda luknja. This is the largest cave system in the so-called isolated karst which consists of limestone patches of <1 to 10 km2 in size in central and northeastern Slovenia. Huda luknja is developed in one of these patches measuring about 1 km2 in the Triassic limestones—the Paka karst. The research focused on the investigation of the epikarst fauna in NE Slovenia. Temperature, conductivity, hardness and concentrations of various ions in water were measured. Considerable spatial and temporal variation in parameters existed among the drips. However, there was no correlation between the community structure and the parameters. There are six aquatic species and 19 terrestrial species in the epikarst of the Paka isolated karst. In the drips, individuals of epigean, epikarstic and hypogean aquatic taxa as well as terrestrial taxa belonging to the same groups as those in caves in the Dinaric karst were found. Unlike the Dinaric karst, the most abundant group was oligochaetes, not copepods. In general, the biotic diversity diminished from the entrance to deep in the cave. More investigation in the isolated karst is required to decide either this is the specific characteristic of this karst patch or a general phenomenon of isolated karst.