The tobacco budworm is an important insect pest of cotton in Mexico, This pest has developed resistance to a wide variety of insecticides commonly used for its control. Pyrethroids have achieved control of this pest, however, intensive use of these products has selected resistant populations. Transgenic Bt cotton is an alternative control method for this and other insect pests in cotton, the area planted with these materials has increased through time in Mexico. The high selection pressure imposed by Bt cotton is a concern, and resistance management strategies have been implemented using refugia with conventional cotton trying to delay resistance. Data obtained up to now have not shown any shift in response to these materials.