The antifungal activity of 81 NSLAB isolates from traditional dairy products against moulds developed on the surface of hard cheeses as well as yeasts was studied. Twenty isolates of facultatively heterofermentative and eleven of obligately heterofermentative lactobacilli from Feta cheese exhibited antifungal activities. These isolates were classified to species level by phenotypic criteria and the SDS–PAGE of whole-cell proteins. The former group also showed a broad spectrum of antibacterial activities with preference towards Listeria monocytogenes and other food-borne pathogens. The extracellular antimicrobial substances were sensitive to proteolytic enzymes, suggesting that the inhibitory activity was due to bacteriocin-like substances.