The undertaken project includes the survey and experimentations. The survey study was conducted to know the farmers'' perception of insect pests and pest management practices in Bt cotton in Punjab, Pakistan. The experimentations were consisted the field and laboratory experiments. The field experiments were conducted to determine the impact of transgenic Bt cotton on the target and non-target insect community in replicated field trials under sprayed and unsprayed conditions, in comparisons with its parent non-Bt conventional cotton. The laboratory experiments were conducted to evaluate the impact of Bt toxin on the biological traits (larval mortality, larval development time and pupal weight) of Helicoverpa armigera and Spodoptera exigua by feeding larvae on the leaves and flower- bolls of Bt and non-Bt cotton. The studies highlight that researchers, technology providers and administrators should ensure the effective and highest level of Bt toxin expression in appropriate plant parts at the requisite time, particularly late in the season.