Two spinosyn compounds, spinosad 12% SC and spinetoram 12% SC were evaluated against housefly under laboratory and field conditions. In field study, the two compounds showed high reduction in fly population especially at the highest rate used (2.4 ml/m²). According to LT₅₀ value spinosad showed relatively higher activity than spinetoram. This indicated that females were more tolerant two spinosyn products than males. In laboratory study the toxicity of spinosad against 1^st and 3^rd instars was higher than spinetoram. The third instar larvae were more tolerant to the two compounds, than the first instar larvae. Against pupae, spinosad showed slightly high toxicity as compared with spinetoram.