The purpose of the present studies was to search for antagonistic microorganisms limiting the occurrence of certain pathogenic soil-borne fungi. The studies were carried out in the years 1999-2001 at Czesławice on an experimental field with naturally accumulated infection material in the soil. The object of the studies was the rhizosphere soil of soybean, cv. Polan. The isolates of bacteria obtained from the rhizosphere of soybean (100 isolated from Pseudomonas spp. and 100 isolated from Bacillus spp.) as well as all the isolates of saprophytic fungi from the genera of Gliocladium, Penicillium and Trichoderma were used to determine their antagonistic effect towards such pathogenic fungi as Fusarium culmorum, F. oxysporum f. sp. glycines, F. solani, Rhizoctonia solani and Sclerotinia sclerotiorum. Laboratory studies showed that the growth and development of the tested phytopathogens were most effectively limited by antagonistic bacteria Pseudomonas spp. and antagonistic fungi Penicillium spp. and Trichoderma spp.