Since the late 1970's synthetic pyrethroid insecticides have become the most widely used cotton insecticides. First to reach full registration were permethrin (Airbush and Pounce) and fenvalerate (Pydrin). Now several others (Ammo, Cymbush, Payoff, Scout, Baythroid, Mavric, Caputre and Danitol) are being evaluated in tests and/or have received some form of registration. All of the currently labeled and tested pyrethroids provide effective control of most of the major insect pests in cotton, i.e. boll weevils and bollworms. They differ considerably, however, in their effectiveness on some of the secondary pests such as cabbage loopers, fall armyworms, and spider mites. Results of several years field tests are discussed with emphasis on the secondary, pest complex in cotton.