Since the beginning of the use of modern synthetic organic insecticides and acaracides on cotton shortly after World War 11, insects and mites have developed resistant strains. As early as the mid-1950's, the bolt weevil developed resistance to DDT and other organochlorine insecticides. Since then every key pest and several secondary pests have developed resistance to one or more of the following insecticides: DDT, cyclodienes (atdrin, dieldrin, endrin, etc.), organophosphates, carbamates and pyrethroids. A review of insecticide resistance with a focus on the U.S. is presented. Fortunately, mixtures of existing compounds or insecticides with new chemistries have always been available most of the time to avert disaster. The latest concerns over synthetic pyrethroid resistance by the tobacco budworm and the pink bollworm again threaten the economic stability of cotton production in certain areas. What lessons have we learned? Will the cycle of resistance repeat itself over and over again in the future? Farmers should definitely be concerned about resistance and its consequences.