The present book entitled “Microbial studies on some traditional medicinal plants. Alternatives in the treatment of oral diseases” is to exploit and evaluate plant extracts as important components of integrated disease management and their efficacy against human pathogenic bacteria was determined through in vitro experimental study. The antimicrobial effect of thirty selective Indian medicinal plants on some standard dental pathogenic microorganisms were studied. Antibacterial activity of isolated secondary metabolites of M.oleifera was represented in this study, Quercetin 3-O-β-D-Glucopyranoside isolated and showed significant zone of inhibition against tested bacteria. Selected nine essential oils were also screened for its antibacterial properties. The oils active against tested bacteria are cinnamon oil, Clove oil, rosemary oil, lemon oil, and tea tree oil. Cinnamon oil showed significantly level of zone of inhibition towards the tested bacteria. Clove oil exhibited significant antibacterial activity against Streptococcus mutans which was comparable to that of the standards, erythromycin and enrofloxacin.