Fifteen pesticides were evaluated against cotton bollworms in Minia region. Reduction in the infestation and larval content was determined before and after three successive sprays with 15 day interval. The effect on cotton yield was considered. During 2006 season the population of the pink bollworm (PBW),Pectinophora gossypiella, was lower compared to the spiny bollworm (SBW), Earias insulana.In general, synthetic pyrethroids exhibited the greatest reduction in bollworm infestation that was associated with the highest amount of cotton yield. In contrast, the bio-pesticide Agrein(B.t.)was not effective against bollworms. The yield in Agrein treatment was not significantly different compared to the control treatment.