When added to liquid media, malathion, MGK®264(N-octyl bicycloheptene dicarboximide), and naled, at concentrations of 100μl/l (insecticide:media), completely inhibited the production of zearalenone (F-2) byFusarium graminearum. F-2 production was completely inhibited in cultures treated with 30 and 10μl/l naled and was reduced by 53% in cultures treated with one μl/l naled. All insecticides except methoxychlor inhibited growth and/or F-2 production by at least 38% at concentrations of 10 and/or 30μl/l. In cultures treated with insecticides at levels of 30–100 μl/l and in those treated with diazinon, naled, dichlorvos, ethion, and pyrethrins at concentrations of 1–10 μl/l, the reduced level of F-2 production was a consequence of reduced mycelial growth. At lower concentrations of one and/or 10 μl/l, azinphosmethyl, malathion, allethrin, Rabon® (2-chloro-1-2,4,5-trichlorophenyl) vinyl dimethyl phosphate), piperonyl butoxide, MGK®264, and mevinphos reduced F-2 production without reducing mycelial growth. Naled was fungicidal at concentrations of 100 μl/l and fungistatic at levels of 1, 10, or 30 μl/l.