Abstract: Present study aimed at the analysis of sensitivity of E. Coli . to Zingiber officinale, Azadirachta indica, Ocimum sanctum and Allium sativum. The ethanolic extract of these four medicinal plants traditionally used in medicine, were studied for their antibacterial activity against the gram negative, E.coli. All the medicinal plant extracts showed inhibitory activity against E. coli. Among the four medicinal plants, Zingiber officinale showed maximum activity against the test microbe. Minimum activity was shown by and Azadirachta indica and Ocimum sativum the lowest inhibition was exerted by Allium sativum. The study comes to the conclusion that medicinal plants which are traditionally used in Ayurveda or in other herbal medical practices have scientific basics and can be modified to produce specific medicines against each bacterium.