Beauveria spp., an entomopathogenic fungus, has recently been widely used as a biocontrol agent of house fly populations to evade the critical effects of chemical insecticides on humans, animals, and the natural ecosystem. In the presented study, different types of fungi were isolated from house flies collected from various locations in different Egyptian governorates between 2021 and 2022. The flies were caught in garbage dumps, dairy and meat production units on cattle farms and poultry farms. The entomopathogenic fungi were identified morphologically and genetically, showing that the isolate was molecularly identified as Beauveria bassiana. This efficacy of the isolated fungal strain against the house fly, M. domestica, was estimated using laboratory bioassay by the immersion method. The isolated fungal strain successfully induced fatal changes with a high mortality rate in the laboratory-reared house flies, which confirms the scientific world researches which has been carried out. The achieved result showed a direct correlation between fungal concentrations and the mortality rate, which reached up to 99.16 %. They also exhibited great destruction and a direct relationship between the increase in spore concentration and the degree of overall DNA genotoxic damage in the exposed fly's DNA to Beauveria bassiana. Beauveria bassiana MN960454.1 can be used as an efficient way for controlling house fly biologically reached up to 99.16 %. Thus, it is recommended to apply Beauveria spp. as a spray in house fly breeding areas.