The antifungal effect of five Lactobacillus strains namely L. plantarum ATCC 4008, L. plantarum 12006, Lactobacillus plantarum 299V, L. paracasei subsp. paracasei LMG 13552 and L.rhamnosus VT1 was examind against some of common cheese-contaminant fungi (A. parasiticus NRRL2999, A. flavus , A. versicolor, Penicillium roqueforti and P. communi). The ability of L. plantarum 299V, L. paracasei subsp < em>. paracasei LMG 13552 and L .rhamnosus VT1 to inhibit aflatoxin B₁ production by Aspergillus flavus and A. parasiticus NRRL-2999 was also studied.All the studied Lactobacillus strains exhibited various degrees of growth inhibition against some but not all the studied molds. The three strains of L. plantarum showed an antimycotic activity against A. versicolor and A. parasiticus but not against A. flavus.   A. versicolor showed the highest sensitivity toward L .rhamnosus and all of L. plantarum strains. This was followed by A. parasiticus which affected at lower extent by L. plantarum strains. Growth of A. flavus was slightly inhibited with the presence of L. paracasei subsp. paracasei and L.rhamnosus only.  On the other hand, none of the studied Lactobacillus strains were found to inhibit growth of P.roquefoti or P. commune. Production of aflatoxin B₁ by A. parasiticus NRRL2999 was almost completely inhibited (98.8-99.99%) by all the investigated lactobacilli. However, the antiaflatoxigenic potential of L. paracasei subsp. paracasei was lower than that of L. plantarum and L. rhamnosus. The amounts of aflatoxin B₁ produced by Aspergillus flavus in the presence of these Lacobacilli were reduced by about 85-92% and 96.3-98.3%  compared with control after 10 and20 days of incubation, respectively.