Abstract: Four pre-emergence herbicides (pendimethalin at 1.48 kg ai/ha. oxadiazon at 0.45 kg ai/ha, trifluralin at 0.75 kg ai/ha and isoproturon at 1.0 kg ai/ha) were tested with three different methods of application, i.e., spray, sand mix broadcast and soil incorporation during spring 1992 and 1993 at NARC, Islamabad. A total of 12 weed species were recorded. The lowest weed density and week biomass was recorded in pendimethalin treatment. Highest plan height and number of pods per plant were obtained from weed free treatment. No negative effect on the germination and growth of the crop was observed. Pendimethalin proved to be the best herbicide for weed control in soybean applied by soil incorporation method. Highest gain yield (1523 kg ha–1) was obtained from weed free treatment followed by pendimethalin (1475 kg ha–1) while the lowest yield (1127 kg ha–1) was produced in weedy check.