Abstract: Onion thrips (Thrips tabaci L.) is a major pest of onion (Allium cepa L.) of family Alliaceae in India and widely spread in summer season. For the control of its infestation, the crop is sprayed intensively with insecticides. In order to find out the most efficient and eco-friendly method of thrips control, an experiment was conducted at Shajapur (M.P.) during the year 2007 and 2008 to assess the thrips population. Thrips population was counted at 15 days interval. Thrips population was peaked in February when they reached the maximum mean values ranging between 15.30 and 153.45 thrips per plant. The seven treatments of insecticides i.e. fipronil 5 % SC, lambda-cyhalothrin 5 % EC, lambda-cyhalothrin 4.9 % CS, thiacloprid 21.7 % SC, deltamethrin 11 % w/w EC, malathion 50 % EC were applied at 30, 45 and 60 days after transplanting of onion crop for management of onion thrips. Among all the insecticides applied fipronil 5 % SC and lambda-cyhalothrin 4.9 % CS was the most effective insecticide in reducing the thrips population and increasing the weight of exportable bulb and yield of onion as compare to control and other insecticides. Fipronil 5 % SC treatment reduced the thrips population by 98.56 percent over control and increased the bulb yield by 124.90 percent compared with control.