The objective of the volume 36 of Recent Progress in Medicinal Plants is to bring together the scientific material relating to essential oils of contemporary pharmaceutical importance. Essential oils are important not only as perfuming and flavouring agent, but also in terms of their putative medicinal or pharmacological properties. This volume aims to describe those important essential oils in a comprehensive and organized manner. Its contributors are from 14 countries namely Brazil, Canada, China, India, Iran, Iraq, Mexico, Nigeria, Romania, Serbia, Slovak Republic, Turkey, United Kingdom and USA. This volume is divided into 18 chapters. The first chapter deals with the characterization and biological activities of essential oils. The second chapter embraces the medicinal applications of essential oils in contemporary therapeutics to treat specific disease conditions of human beings. The third chapter describes the essential oil use in ethnoveterinary medicine in British Columbia, Canada. The neuropharmacology of essential oils is explained in the fourth chapter. The fifth chapter deals with the role of essential oil constituents in renal diseases. The medicinal and biological properties of hydrosols and water soluble essential oils are explicated in the sixth chapter. The next chapters individually elaborate the biological and therapeutic properties of 13 important essential oils. The facts and findings presented in the present volume would serve as basic as well as applied scientific material for further work in developing newer and effective therapeutic agents, flavouring agents, cosmetics and insecticides from essential oils. This special volume is designed for professionals of interdisciplinary health sciences, food technology, pharmaceutical sciences, pharmacognosy, pharmacology, agriculture, botany, medicine, therapeutics, traditional medicine, complementary and alternative medicine, aromatherapy, herbalism, medical and public health sciences, healthcare professionals of other various disciplines, policy-makers and marketing and economic strategists. It is addressed to undergraduates, post-graduates, teachers and researchers.