This study assessed the impact of an alcoholic extract of Citrus aurantium leaves on the mortality percentages in the larvae and pupae of house flies, Musca domistica, and was carried out in the Advanced Entomology Laboratory in the Department of Biology at the Girls College of Education at the University of Kufa in 2022. The results indicated an increase in the mortality percentages of larvae in the first and third stars of the house fly, Musca domistica with increasing concentrations used. In this study, the highest mortality percentages were recorded after three days of treatment with a concentration of 50 mg/ml (100 and 61%) in the first and third instar larvae, respectively. The effect of the alcoholic extract on some biological aspects when treating the third instar larvae of houseflies, as it led to a decrease in pupation percentages to 24% when treating pupae with a concentration of 50 mg/ml, and the pupal deformation percentages to 24% and a decrease in adult emergency percentages to 0% when treating pupae with the alcoholic extract of Citrus aurantium leaves at a concentration of 50 mg/ml, which increased the pupal deformation to 50% and decreased adult emergency percentages to 50%.