A field experiment was conducted at Palampur during the kharif seasons of 2004, 2005 and 2006 to standardize the doses of new herbicides (acetachlor, trifluralin, haloxyfop and quizalofop) in soybean under mid hill conditions of Himachal Pradesh. Haloxyfop at 0.100 kg/ha (72.0%) and acetachlor 1.50 kg/ha (72.3%) resulted in highest weed control efficiency among post- and pre-emergent herbicides, respectively. Haloxyfop at 0.100 kg/ha and quizalofop at 0.0625 kg/ha were effective against grassy weeds (Panicum, Echinochloa and Digitaria). Acetachlor was most effective against grassy as well as broad-leaved weeds (Ageratum conyzoides, Polygonum alatum and Commelina benghalensis). Haloxyfop at 0.100 and 0.125 kg/ha, quizalofop 0.0625 kg/ha, acetachlor 1.50 kg/ha and trifluralin 1.50 kg/ha resulted in significantly higher plant dry weight, branches/plant, pods/plant, seeds/pod, 1000- seed weight and seed yield of soybean. Haloxyfop 0.100 kg/ha resulted in highest net return and B : C ratio. Weed management index (WMI), agronomic management index (AMI) and integrated weed management index (IWMI) were highest in haloxyfop-methyl 0.100 kg/ha followed by quizalofop 0.0625 kg/ha, haloxyfop-methyl 0.125 kg/ha and trifluralin 1.50 kg/ha.