Thirteen dairy bacteria strains belonging to the genera Streptococcus, Lactobacillus and Bifidobacterium and four commercial lactic cultures (Visbyvac Joghurt 709, MyBIO2 Ezal, LBA Ezal, BL Ezal) were screened for antifungal activity against Aspergillus (A.) flavus NRRL 2999, A. parasiticus, Penicillium (P) expansum, Fusarium poae, Mucor spp. and Geotrichium spp. and the yeasts Candida (C.) rugosa Cr1, C. vini Cv1, Saccharomyces cerevisiae NCYC738, Saccharomyces cerevisiae Sc5, Debaryomyces hansenii Dh2 and Debaryomyces hansenii Dh3. Among the mould cultures, P expansum was found the most sensitive indicator culture against antifungal substances produced by the test bacteria. Lactobacillus (L.) delbrueckii subsp. bulgaricus NCC 855, L. delbrueckii subsp. bulgaricus NCC 861 and commercial yogurt culture (Visbyvac Joghurt 709) completely inhibited mycelium growth of P expansum. The cell free supernatant of Bifidobacterium longum NCC 435 produced an inhibition zone of 2-4 mm against C. rugosa. However, other lactic acid bacteria did not have an effect on mould and yeast growth.