Анотация: Several Fusarium species are important pathogens of cereals and corn, causing severe crop yield reduction. In addition, some isolates are able to produce mycotoxins. The most important Fusarium mycotoxins, which can frequently occur at biologically significant concentrations in cereals, are fumonisins, zearalenone (ZEA) and trichothecenes (deoxynivalenol, nivalenol and T-2 toxin). The aim of the current study was to establish ZEA-producing activity of some wheat Fusarium species (F.graminearum and F. oxysporum) originated from different geographical regions in Bulgaria. 40 wheat Fusarium isolates were screened for their ability to produce ZEA, by cultivating on the sterile wheat