A field experiment was conducted during kharif 2011 to study the effect of sequential application of herbicides for weed control in Bt cotton. Ten weed control treatments were tested in randomised block design replicated thrice. All the herbicide treatments significantly reduced dry weight of weeds over un weeded control. Among the herbicide treatments sequential application of Pyrithiobac sodium at 0.125 kg ha-1 as pre emergence followed by (fb) the same herbicide at 0.125 kg ha-1 as post emergence, Butachlor at 1.5 kg ha-1 fb Butachlor at 1.5 kg ha-1 and Pendimethalin 38.7% CS 0.68 kg ha-1 fb Pendimethalin 38.7% CS 0.68 kg ha-1 were quite effective in controlling weeds which reflected in significantly decreased weed dry weight and increased weed control efficiency. These three herbicide treatments also recorded significantly higher kapas yield (3255, 3234 and 3145 kg ha-1, respectively). The growth and yield parameters followed similar trend as that of kapas yield. The weed index was also lower in the above three treatments (6.83, 7.39 and 10.20 %, respectively) compared to un weeded control (73.60%).