Pakistan is the world’s fourth largest producer and third largest consumer of cotton. Using data from 16 villages in two cotton-growing districts of Pakistan, we attempt to determine the impacts of Bt cotton adoption on producers’ wellbeing employing the propensity score matching method. While the results reveal positive impacts of Bt cotton on the wellbeing of farmers in Pakistan, the extent of impact varies by agro-climatic conditions and by farm size. The impact of Bt cotton adoption on yield for small farmers is about is about 50 percent of the same for large farmers. Similarly, the impact of Bt cotton adoption on household income was positive and significant for medium and large farmers but not for small farmers. The impacts of Bt cotton on yield and income are larger under hot and humid conditions than under hot and dry climatic conditions. Additional public-sector investments in monitoring and assessments of pest infestations across climatic zones would be helpful to make the Bt cotton technology widely beneficial in Pakistan.