We evaluated 214 lines of wild oat (Avena fatua L.) for response to S-2,3-dichloroallyl N,N-diisopropylthiolcarbamate (diallate), S-2,3,3-trichloroaHyl N,N-diisopropylthiolcarbamate (triallate), and 4-chloro-2-butynl m-chlorocarbanilate (barban). We found large differences among the lines in response to these herbicides and some lines that might not be controlled by recommended rates of these herbicides. Frequency distributions of response to herbicides suggest that reaction to these three herbicides is quantitatively inherited. We were unable to establish a relationship between morphological characteristics and plant response to these herbicides.