Housefly resistance to DDT and lindane in Egypt was first reported 17 years ago, yet these insecticides continue to be used.The present degree of housefly resistance to DDT and lindane was found to be high, and cross-resistance to dieldrin was discovered. An analysis of dieldrin resistance was made, and it was found that a single selection with dieldrin at a high selection pressure resulted in a homozygous resistant strain. The strains were found to be still susceptible to organophosphates and carbamates, some of which could be chosen for housefly control in Egypt.