Background <p>Housefly, <i>Musca domestica</i> L., causes a variety of health problems for humans and animals. Therefore, the management of houseflies is crucial to prevent health threat caused by diseases transmitted by this vector.</p> Methods <p>Insecticidal activity of five microbial insecticides against larvae and adults of <i>M. domestica</i> was assessed under laboratory conditions. To evaluate the toxicity against for third instar larvae, the microbial insecticides, abamectin (AB), emamectin benzoate (EB), ivermectin (IV), spinosad (SP) and spinetoram (SI), were mixed individually with food-media at concentrations of 0.05, 0.1, 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0&#xa0;mg/kg, while in case of adults, the insecticides were tested at 0.001, 0.01, 0.05, 0.1, 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0 ml/L in sugar water solution.</p> Results <p>The results showed that all tested microbial insecticides were highly toxic against larvae. The maximum larvicidal activity was achieved by EB with LC₅₀ value of 0.05 mg/kg, followed by AB, IV, SP and SI with LC₅₀ values of 2.02, 2.05, 2.09 and 8.06 mg/kg after 72 h of exposure, respectively. Likewise, treatments with EB (4.0 mg/kg) and AB (8.0 mg/kg) caused a complete suppression of adult emergence and a strong reduction of pupation (0.0 and 37.5%), respectively. Furthermore, the three microbial insecticides, AB (LC₅₀ = 0.04 and 0.03 ml/L), EB (LC₅₀ = 0.05 and 0.03 ml/L) and IV (LC₅₀ = 0.10 and 0.03 ml/L), showed a strong toxicity against <i>M. domestica</i> adults after 24 and 48 h of exposure, respectively.</p> Conclusions <p>Based on these findings, the investigated microbial insecticides, especially EB and AB, could be applied in IPM programs of <i>M. domestica</i>.</p>