Cotton the most important commercial crop of India, often referred as the White Gold, consumes more than 45% of the total pesticides used in our country. The most important insect pests that affect cotton production are jassids, white fly, aphids and thrips among the sap sucking pests and boll worms (American, Pink and Spotted) and Spodoptera among the leaf eating caterpillars. Of these cotton pests, the American boll worms alone cause yield reduction upto 40-70% under severe incidence. The genetic resistance, one of the important pest management strategies, is available in cotton gene pool against the sap sucking pests, whereas such resistance is not available against the bollworms. Hence, an alternate strategy is explored to circumvent this problem by cloning and transferring the genes encoding the toxic crystal δ-endo toxin protein from the soil bacterium Bacillus thuringiensis. The Bt transgenic cotton (Bollgard of Monsanto) has thus been developed successfully in USA, which has the ability to control the bollworms during crop growth effectively. Ever since three Bt cotton hybrids have been approved for commercial cultivation in India during 2002, there was a sharp increase in area under cultivation of such hybrids from a mere 72,000 ac in 2002-03 to 30,00,000 ha in 2006-07. So far, 59 Bt hybrids have been approved in different cotton growing zones by GEAC (Genetic Engineering Approval Committee, Government of India) after extensive field trials by All India Coordinated Cotton Improvement Project centres and RCGM trials in farmers’ fields. Bt cotton hybrids exhibited excellent control of American Boll worm and reduced the use of insecticides leading to create eco-friendly environment without compromising on profitable yield. As compared to insecticide mediated control of bollworms, Bt cotton technology does not harm non-target beneficial insects; besides reduction in production cost, increase in profit, reduced farming risk and improved economic outlook for cotton are the highlights of this novel technology. Use of this technology is also helpful in improving wild life population, reduced run-off of insecticides, reduced air pollution and improved safety to farm workers and neighbourhood.