Green peach aphid, Myzus persicae, is one of major pests attacking greenhouse pepper plants in Korea. We examined a pyrethrum emulsion for the control of M. persicae. The emulsion was prepared by blending natural pyrethrum extracts with food-acceptable components. The emulsion produced a clear aqueous solution when diluted in water. Laboratory evaluation showed an average 80% mortality of 2nd-instar nymphs after treatment at 100 mg/L natural pyrethrum. The aphid mortality data were a dose-response relationship for the emulsion. Field trials in two greenhouses showed aphid mortalities from 59.6 to 100% with 100 mg/L natural pyrethrum. No significant differences in aphid mortality between the two greenhouses were observed. This study shows that it is possible to prepare a one-phase clear emulsion of natural pyrethrum using food-acceptable components to control M. persicae. Pesticide formulations using food-acceptable components are suggested to play a role in protecting the public and environment from potential threats of botanical pesticides.