The experiment was conducted to evaluate the efficiency of pre­mpt (fenpropathrin + pyreproxyphen) at the rates of 400 ml. and 300 ml./fed. and its mixture with mineral oil, cottonseed oil and acetic acid against whitefly Bemisia tabaci (Genn.) and both cotton bollworms; pec­tinophora gossypiella (Saund.) and Earias insulana (l3oisd.) at EI-Gemmiza Agricultural Research Station during 1996 cotton growing season. Sum­merized results showed that prempt could be used at the rate of 300 ml./fed. which it was equitoxic to the prompt at the rate of 400 ml./fed. for controlling mature and immature stages of the cotton whitefly and cotton bollworms. This in turn minimized both pollution and costs of spray. No need was found to add any of mineral or cottonseed oil or acetic acid as having no effect on the toxicity of such compound .