Medicinal herbs that are in use for centuries to treat infections and other illnesses. Prunella vulgaris L. is traditionally used for its therapeutic attributes for the alleviation of various infectious diseases. The objective of this study on Prunella vulgaris was to reveal relevant pharmaceutical information to understand its beneficial medicinal uses for human beings. The methanolic and petroleum ether extracts after removal of the solvent under reduced pressure from the Prunella vulgaris plants were prepared and these extracts were analyzed in vitro for their activity against B. subtilis, E. coli, S. aureus and S. typhi (with ATCC numbers 6051, 25922, 23235 and 14028 respectively). Likewise, in vivo studies were conducted using the E. coli-induced peritonitis in laboratory rat models where the rats were given allopathic antibiotic ofloxacin and the results were compared with those rats who received plant extracts under controlled conditions. The results were analyzed for the efficacy of the plant extracts was compared with ofloxacin; the methanol extracts exhibited equally if not better results in clearing the pathogen from the system of animals. The petroleum ether extracts exhibited the least antimicrobial activity in comparison to those extracted in methanol isolates. In conclusion, the herbal extract demonstrated significant antibacterial activity both under in-vitro and in-vivo studies which is a major outcome of the study. During this study, all standards and norms were followed as per government animal authority.