A field experiment was conducted at Birsa Agricultural University, Kanke, Ranchi, during the year 2016-17 to study the effect of herbicides on growth, yield and quality of onion. The treatments comprised of application of oxyfluorfen (0.25 kg/ha) one week before transplanting, oxyfluorfen (0.25 kg/ha) immediately after transplanting, pendimethalin (1.00 kg/ha) one week before transplanting, pendimethalin (1.00 kg/ha) immediately after transplanting, pretilachlor (0.75 kg/ha) one week before transplanting, pretilachlor (0.75 kg/ha) immediately after transplanting, quizolofop-ethyl (1.00 kg/ha) 20 days after transplanting (DAT), hand weeding (HW) and weedy check. Results revealed that highest plant height (66.67 cm), number of leaves (5.98) and neck thickness (4.76 cm) were recorded in hand weeding at all the growth stages, which was at par with pendimethalin immediately after transplanting and pendimethalin one week before transplanting.The increase due to HW was in the tune of 78.88, 55.73 and 59.20% respectively than weedy check whereas, pendimethalin immediately after transplanting of onion recorded 63.94, 52.56 and 51.84% increase over weedy check. Hand weeding recorded 122% more yield (23.71 t/ha) than weedy check (10.68 t/ha). Juice content and TSS was the highest in hand weeding which was at par with pendimethalin immediately after transplanting, application of pendimethalin one week before transplanting and oxyfluorfen immediately after transplanting.