The house fly is one of the most important medical and veterinary insects for humans and farm animals. In the current study, the effect of two compounds of plant extract was evaluated against the larvae of the house fly, Musca domestica (Diptera: Muscidae), ethanolic extract of lemongrass plant Cymbopogon citratus L.), and the nanoparticles of the extract of the same plant. The effect of both compounds against housefly larvae and pupae resulting from larvae treated using the technique of feeding and dipping were compared. The results showed that the feeding technique is more effective against larvae when compared with the dipping technique. The results also indicated that the nanoparticles of the plant extract were more effective against larvae, which led to an increase in the period of larvae and pupae, and an increase in death rates in each of them, also led to deformities in the adult insects resulting from the treated larvae compared to the control. Treatment with the compounds caused some biochemical changes, where the treatment with nanoparticles of the plant extract caused significant increasing in the levels of total protein, total carbohydrates, total lipids and acetylcholinesterase activity (Ach E) compared to the control in the larval stage. As for the pupae resulted from treated larvae, the treatment resulted in a significant increase in the case of using nanoparticles of the plant extract in all the tested biochemical indicators. Therefore, nanoparticles can be used to control house fly larvae, with further study to know the effect of these particles.