A survey of 160 growers in the Mississippi Delta in 1996 was conducted to obtain data on cotton insect control costs for that production year. Each interview conducted with a farmer in the sample provided data on a typical cotton field on that farm for conventional cotton and Bt varieties if they were grown on that farm. An analysis of these data indicate that there was no meaningful difference in insect control costs when the technology fee of $32 per acre was added to the Bt varieties. These data indicated a reduction in costs of control for the tobacco budworm and to a lesser degree for the cotton bollworm. However, due to the low number of applications for these two pests, insect control costs for boll weevil and tarnished plant bug were greater on fields where Bt cotton was grown. Yields as reported by farmers indicated that the conventional varieties produced 73 pounds of lint per acre more than the Bt variety when data from all farms were considered. However, a direct comparison of both Bt and conventional yields on the same farms indicated a yield difference of only 47 pounds per acre advantage to the conventional cotton.