The selective action of MSMA, benzoylprop-ethyl, nitrofen, dichlormate, terbutryne and methabenzthiazuron and their combinations with 2, 4-D for control of grass weeds in spring wheat (Triticum aestivumL.) was studied in two field experiments at Haryana Agricultural University, Hissar, India, during 1975–76 and 1976–77. The differences in response among wheat, wild canarygrass, wild oats and broadleaved weeds to post-emergence herbicides were very variable. Methabenzthiazuron at 1.75 and 2.0 kg/ha and terbutryne at 0.60 to 0.75 kg/ha sprayed in the wheat crop at maximum tillering stage killed more than 70% of wild canarygrass (Phalarisspp.) and wild oats (Avenaspp.) with no injury to the crop plants, resulting in the highest grain yield. The application of 2, 4-D (0.50 kg/ha) controlled only 55% wild canarygrass and 40% wild oats but significantly increased the wheat yields over the unweeded control. The other post-emergence herbicides were not effective in controlling both weeds selectively. 2, 4-D in combination with various herbicides was phytotoxic to the crop.