Field experiment was carried out for two seasons at Agricultural Research Station, Dharwad Farm, Dharwad-580 007 (Karnataka, India) to evaluate the performance of different new generation Bt cotton genotypes under rainfed eco-system. Second generation genotypes MRC-7201 and MRC-6322 with Cry1Ac + Cry2Ab genes have shown high level of resistance to all the three species of bollworms. The incidence of bollworms did not cross ETL in BG-II hybrids. First generation Bt intraspecific hybrids with Cry1Ac  have received one and interspecific hybrids received two sprays. MRC-7201 recorded 0.13 larva of H. armigera per plant and 4.98 per cent fruiting body damage. MRC-6322 BG-II was on par with MRC-7201. RCH-368 Bt found better with 0.1 larvae per plant of E. vittella and 0.54 H. armigera larvae per plant and 5.73 per cent fruiting body damage among genotypes with Cry1Ac. Interspecific Bt hybrids MRC-6918 and RCH-708 performed better under protected conditions. All Bt hybrids were effective in containing pink bollworm incidence. Seed cotton yield was 20.58q/ha and 18.47 q/ ha in MRC-7201 and MRC-6322 BG-II hybrids respectively without any protection against bollworms.