Heads of 12 spring barley genotypes (eight cultivars, four lines) were inoculated with conidial suspensions of two Fusarium culmorum isolates (I1 and 12). Both isolates caused the following significant reductions (%) when compared with the control: number of kernels head-l 12 and 16, weight of 1000 kernels 47 and 24, yield 49 and 37, for Iland I2 respectively. Both isolates were able to produce average levels (mg kg-1) of deoxynivalenol of 67.1 and 13.9, 3-acetyldeoxynivalenol of 9.4 and 1.4 and zearalenone of 0.3 and 0.4 for 11 and I2 respectively. In kernels of three genotypes inoculated with the same isolates, 15-acetyldeoxynivalenol at an average level (rag kg-1) of 1.3 and 1.5 was detected, while in kernels of six genotypes inoculated with I2, 0.2 of nivalenol was found. A significant correlation for yield and toxin level was found for less pathogenic F. culmorum isolate I2.