Approximately 55% of Mississippi's 930,000 acres of cotton were planted to Bt-transgenic varieties in 1998. A field survey was conducted during late season to compare performance of Bt and non-Bt varieties. Bt fields sustained significantly less caterpillar induced boll damage, 2.55% vs 4.81%, and received significantly fewer foliar insecticide treatments for control of bollworm and tobacco budworm, 1.22 vs 5.18. However, in the Delta region of the state, Bt fields sustained significantly more boll damage due to tarnished plant bug and received significantly more treatments for control of boll weevils. Although the Bt variety Stoneville 4740 received significantly more foliar sprays to control bollworm, it also sustained significantly more caterpillar induced boll damage than the average for all other Bt varieties.