Monograph is devoted to the antimicrobial (antibacterial and antifungals) properties of the essential oil which have gotten from aromatic plants of Azerbaijan flora. It provides information about the general characteristics of the essential oil plants, essential oil, chemical composition, properties and application. There has been shown to be highly antimicrobial properties of essential oil against gram-positive and gram-negative bacteria and yeast which have gotten from plants that spread in Azerbaijan area. The book may be useful for scientists, microbiologists, pharmacologists, doctors in the related specialty, high school teachers and students.