Eucalyptus is a tall, evergreen tree, local to Australia and Tasmania, effectively presented around the world, now broadly developed in numerous different nations including India. It found to different properties like anti bacterial, antifungal, anti cancer etc. Thus, the aim of this study was to examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus (E. globulus) against pseudomonas aeruginosa. We have observed that, clinical isolates of P. aeruginosawere inhibited from 0.25-2% of eucalyptus oil.The MIC of ginger oil was appeared to be 0.25% for P.aeruginosa. The eucalyptus oil is found to have antibacterial activity against P. aeruginosa.