A field experiment was conducted with fourteen treatments (oxadiarzyl 0.180 kg/ha, pendimethalin 1.50 kg/ha, trifluralin 1.50 kg/ha and isoproturon 1.25 kg/ha alone and at half rate with hand weeding (HW), oxadiarzyl, pendimethalin and  trifluralin each at half rate followed by (fb) isoproturon 0.75 kg/ha (post), pendimethalin fb clodinafop each at half rate, hand weeding  twice and weedy check) at Palampur during Rabi 2006-2007 and 2007-08. Phalaris minor (28.2%), Avena ludoviciana (25.2%) and Lolium temulentum (19.2%) were the predominant grassy weeds. The broad-leaved weeds (Vicia sativa, Coronopus didymus and Anagallis arvensis) as a whole constituted 26.7% of the total weed flora. Hand weeding twice and pendimethalin fb isoproturon were more effective in reducing the population of P. minor. Pendimethalin + hand weeding and hand weeding twice were effective against A. ludoviciana. Similarly integration of one hand weeding with isoproturon and trifluralin and hand weeding twice effectively taken care of L. temulentum. Pendimethalin + isoproturon and hand weeding twice reduced N and S removal by weeds. Pendimethalin fb isoproturon and trifluralin fb isoproturon resulted in significantly higher yield attributes (silique/plant, seeds/silique, 1000-seed weight), seed yield and seed N per cent of mustard. Trifluralin + HW and pendimethalin fb isoproturon gave higher gross and net returns due to weed control over other treatments. Isoproturon resulted in highest net return per rupee invested on weed control (18.5).