The present study was examined the effect of two IGRs (pyriproxyfen & chlorfluazuron) on the external bacterial flora isolated from the Pharaoh ant workersMonomorium pharaonis (L.). The Pharaoh ant workers were collected from three different cities in Cairo governorate. Different concentrations of 0.1%, 0.5%  & 1% pyriproxyfen and 0.001%, 0.01% & 0.1% chlorfluazuron were used. Bacteria associated with Pharaoh ant workers (indoors & outdoors collected samples) were isolated before and after treatment with IGRs. It was found that, the external bacteria isolated from outdoors samples were less counted than those collected from indoors.The presence of some pathogenic bacteria was recorded. The used IGRs cause significant reduction in the count of bacteria in external isolates. Kinds of isolated bacteria were also affected by IGRs treatment and some kinds of them were disappeared in treated samples.