An experiment was conducted at PAU, Ludhiana, during the rabi seasons of 2006-07 and 2007- 08 to study the effect of different planting patterns and straw management techniques on residues of different herbicides in onion bulbs and soil. The experiment was laid out in split plot design with planting patterns of onion (flat and bed planting with and without rice straw incorporation) in main plots and weed control treatments in sub-plots. Oxyflourfen and pendimethalin were applied one week after sowing (after first irrigation) and fluchloralin was applied as pre-plant at their respective doses as per given herbicidal treatments. Soil samples were collected from the experimental plots at 1, 30 and 60 days after spray and at uprooting from each plot from 0-15 and 15-30 cm depth and samples of onion bulbs were taken at 30, 60, and 90 days after spray and at uprooting. Soil samples of oxyflourfen 0.225 kg/ha, pendimethalin 0.75 kg/ha and fluchloralin 1.125 kg/ha treated plots taken 1 day after spray showed residues of respective herbicides. Samples of onion bulbs at 30, 60 and 90 days after spray and at uprooting stage showed no residues of applied herbicides in onion bulbs.