10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 4 2015 (October - December) Plants produce certain bioactive compounds which are naturally toxic to microorganisms and so have been investigated as therapeutic agents. The present study was carried out so as to evaluate the antimicrobial effect of essential oils of few aromatic medicinal plants namely, Lemongrass, Pongamia, Ocimum and Sandalwood. In vitro evaluation was done for individual oils as well as a combination of the oils, two at a time, in 1:1 ratio against bacterial pathogens. Test cultures used were namely lessThan i greaterThan Staphylococcus aureus, Pseudomonas aeruginosa lessThan /i greaterThan and lessThan i greaterThan E lessThan /i greaterThan . lessThan i greaterThan coli. lessThan /i greaterThan The synergistic action was tested that is the combination formula with two assumptions, one that individual oil may show ineffectiveness if used repeatedly as seen in antibiotics and second the combined formulation may show the wider range of antimicrobial activity. In vitro assay was also carried out using commonly used antibiotics against these pathogens and compared with the synergistic effect of herbal extracts. The study showed promising results for the use of Lemongrass, Pongamia, Ocimum and Sandalwood in specific combination against sepsis causing lessThan i greaterThan Staphylococcus aureus, Pseudomonas aeruginosa lessThan /i greaterThan as well as leading nosocomial agent lessThan i greaterThan E. coli. lessThan /i greaterThan SNEHA GOGTE AND B.SAI KRUTHI Antibiotics, Antibacterial properties, Bacterial pathogens, Essential oils, Synergistic effect 101-106