A field experiment was conducted at PGI farm, M.P.K.V., Rahuri during Kharif, 2012. The experiment was laid out in randomized block design with three replications and nine treatments consisted of different weed control treatments, viz. weed free, weedy check (control), pendimethalin 1.0 kg/ha (PE) fb 1 HW at 45 DAT, oxyfluorfen 0.150 kg/ha (PE) fb 1 HW at 45 DAT, quizalofop-ethyl 0.05 kg/ha at 21 DAT (POE) fb 1 HW at 45 DAT, pendimethalin 1.0 kg/ha(PE) fb oxyfluorfen 0.25 kg/ha at 45 DAT (POE), pendimethalin 1.0 kg/ha(PE) fb quizalofop-ethyl 0.05 kg/haat 45 DAT  (POE), pendimethalin 1.0 kg/ha(PE) fb quizalofop-ethyl 0.037 kg/ha+ oxyfluorfen 0.18 kg/haat 45 DAT (POE), quizalofop-ethyl 0.037 kg/ha+ oxyfluorfen 0.18 kg/haat 21 DAT (POE) fb 1 HW at 45 DAT. The onion, cv. ‘Baswant-780’, was transplanted on ridges and furrow. The lowest weed population, weed biomass, weed index and higher weed control efficiency were recorded in weed free check and were at par with application of quizalofop-ethyl 0.037 kg/ha+ oxyfluorfen 0.18 kg/ha at 21 DAT (POE) fb 1 HW at 45 DAT which was followed by spraying of pendimethalin1.0 kg/ha (PE)  fb quizalofop-ethyl  0.037 kg/ha + oxyfluorfen 0.18 kg/ha at 45 DAT. Pendimethalin1.0  kg/ha (PE) fb quizalofop-ethyl 0.037 kg/ha + oxyfluorfen 0.18 kg/ha at 45 DAT proved to be the most remunerative weed control treatment, which recorded the highest benefit: cost ratio (3.48). However, the highest net monetary returns (` 1,67,839/ha) was recorded quizalofop-ethyl 0.037 kg/ha + oxyfluorfen 0.18 kg/ha at 21 DAT (POE) fb1 HW 45 DAT with benefit:cost ratio of 3.39.