The influence of culture fluid of a yeast-like fungus, melanin producer Pseudonadsoniella brunnea (Meripilaceae, Agaricomycotina) on pathogenic fungi of the genus Gibberella (anamorph of Gibberella fujikuroi, i.e.: Fusarium verticillioides) (Nectriaceae, Ascomycotina) is studied by using the agar diffusion method. The stable fungicidal effect of Ps. brunnea culture fluid on pathogenic fungi investigated found to be present. The diameter of the zones of absence of growth of test cultures of pathogenic fungi, those testified the fungicidal impact of Ps. brunnea culture fluid, found to be similar to the action of biocides belonging to the class of quaternary ammonium compounds (benzalkonium chloride).