Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), commonly referred to as the cotton bollworm and corn earworm, is a polyphagous pest of multiple crops including cotton, corn, grain sorghum, soybeans, and tomatoes. One of the most common and inexpensive chemical control measures for this pest is the use of pyrethroid insecticides. Over the last five years, the Texas A&M University Insect Toxicology Laboratory has monitored H.zea resistance to cypermethrin across the state of Texas using the Adult Vial Test (AVT) that exposes pheromone trap-collected adult male moths to different concentrations of cypermethrin residues on 20 ml glass vials. LC₅₀ and LC₉₀ values and resistance ratios were determined for a susceptible H. zea colony and the F1 generation of H. zea larvae collected from a Nueces Co. grain sorghum field in June 2007, using the following methodology: neonate vial assay, third instar vial assay, adult vial assay, neonate leaf dip assay, and third instar leaf dip assay. Results of these experiments and implications are discussed.