A field experiment was conducted at Agricultural College farm, Raichur during kharif, 2008 to find out the performance of Bt cotton genotypes with different plant densities under rainfed condition. Bunny Bt BG-II recorded significantly higher seed cotton yield (23.55 q ha-1) followed by Bunny Bt BG-I (21.83 q ha-1). Bunny Bt BG-II performed better with respect to growth components viz., number of sympodial branches per plant (22.53), dry matter production (450.4 g plant-1), leaf area (106.5 dm2 plant-1), leaf area duration  (177.61 DAS), leaf area index  (4.58), AGR (5.18 g day-1) and crop growth rate  (22.4 mg dm2 plant-1). Significantly higher boll weight (3.53 g) and harvest index (0.246) were recorded with Bunny Bt BG-II. Spacing of 60 x 30 cm recorded significantly higher (21.11 q ha-1) seed cotton yield than wider spacing of 90 x 60 cm (15.59 q ha-1), 75 x 30 cm (18.85 q ha-1) but it was on par with 90 x 20 cm (20.10 q ha-1). However, the differences in seed cotton yield due to both Bt hybrids and closer spacings did not differ significantly.