Strains of the tobacco budworm, Heliothis virescens (F.), collected in Mississippi were evaluated in bioassays to four classes of insecticides. High levels of resistance were found to cypermethrin, methomyl, and thiodicarb. Significant resistance to Bacillus thuringiensis Berliner was not observed during the season. Multiple resistance is still apparent and resistance to pyrethroids appears to be increasing.