Propolis ethanolic extract (PEE) at 3 and 4 g/L and ultragriseofulvin (UG) at 0.75 and 1 g/L reduced the percentage of conidia germination in two Aspergillus flavus isolates. PEE at 1-4 g/L decreased the mycelial dry mass of A. flavus isolates by 11-80%, and aflatoxin B1 production by 34-100%. UG concentrations of 0.25-1 g/L reduced the growth and aflatoxin B1 production of the isolates by 16-88 and 48-98%, respectively. Any increase in PEE and UG concentration was accompanied by a clear decrease in the per cent conidia germination, growth and aflatoxin B1 production. At equal concentration, UG was about 4-times more effective than PEE.