Considering the pace at which multi-drug resistant pathogenic microorganisms are emerging, there is an increasing need to discover new and more effective antibiotics. To this aim, the scientists are looking for novel microbes in understudied environments, such as caves, that could potentially provide us with new source of antibiotics. The eighty-seven cave bacteria isolates we used in our research, were obtained in Pajsarjeva jama near Vrhnika. We then screened those isolates, against ten Gram positive and Gram negative multidrug resistant strains. Isolates belonged to genera Streptomyces, Micrococcus, Rhodococcus, Pseudomonas, Agrobacterium, Lysobacter, Bacillus, Sphingomonas in Kocuria. Each one of the isolates has exhibited at least one antimicrobal avtivity against multidrug resistant strains. The high proportion of antimicrobial-producing strains suggests that caves may represent a potential reservoir of novel bioactive compounds.