A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore during winter seasons of 2015-16 and 2016-17 to evaluate the effect of time of sowing and weed management methods on Bt cotton hybrid. Different time of sowing and weed management methods play a significant role in determining weed incidence, crop growth and productivity of Bt cotton in Western Zone of Tamil Nadu. Results revealed that, early time sowing of Bt cotton on 1st August with pre-emergence application of pendimethalin 0.68 kg/ha followed by post-emergence application of pyrithiobac sodium 62.5 g/ha recorded significantly lower total weed density, dry weight and higher weed control efficiency with better performance of cotton growth, higher yield attributes, seed cotton yield and economics during both the years.