Three wild oat herbicides benzoylprop-ethyl, flamprop-isopropyl and flamprop-methyl were each applied in mixtures with the chlorophenoxy herbicides 2,4-D, dichlorprop, MCPA and mecoprop. The effect of the mixtures on Maris Dove oats was studied. All mixtures induced significantly less suppression of growth in oats than that induced by the wild oat herbicides alone at the lower rates. This effect demonstrated the existence of antagonism between the three wild oat herbicides and the four chlorophenoxy compounds tested. Antagonism was inversely related to the amount of wild oat herbicide present in the mixture.