On account of the pivotal role of herbal compounds in all scientific research, this study aimed to detect the effect of garlic essential oil nanoemulsion (GON) on Trueperella pyogenes (T. pyogenes). Four isolates of T. pyogenes were grown on brain heart infusion agar and used to extract the bacterial DNA to detect 16 SrRNA and rpoB genes. The physicochemical characteristics of GON were analyzed through GC-mass analysis and Nanotrac-Zeta sizer. Using the transmission electron microscope, the antibacterial activity was studied by minimum inhibitory concentration. All isolates used were positive for 16S rRNA and rpoB genes. The average Garlic oil nanoemulsion size was 118 nm with significant homogeneity. Garlic essential oil nanoemulsion has a negative charge with automatic polarity with 89 us/cm conductivity. Garlic essential oil nanoemulsion was safe to use, and the fatty acids, mainly oleic and stearic acids, were its major particulars. Garlic oil nanoemulsion has deleterious effects on T. pyogenes as it causes cell lysis, cytoplasmic leakage, and nanoparticle clusters on the bacterial cell. Furthermore, it resulted in alterations to the exterior surfaces, interior characteristics, and biological activity of the cells, so it should be studied on a large scale, and a trial to explore in vivo efficacy of this product should be done. Trueperella pyogenes 16S rRNA rpoB gene Garlic oil nanoemulsion mass analysis