In the wake of energy crisis, the alternatives for energy sources are much demanded. This method suffers from several disadvantageous including losses in the volatile compounds,long extraction time and degradation of some compounds through thermal process. The diversity among the components of the plants has resulted in their use in many applications including in flavors as well as in medicine. Microwave heating has an incontestable place in analytical and organic laboratory practices as a very effective and non-polluting method of activation. The conventional methods for the extraction of essential oils are hydrodistillation (HD), soxhlet, in which the the essential oils are evaporated by heating a mixture of water and plant materials followed by the liquefaction of the vapors in a condencer. The use of herbs and plants in food industry has a long history. In this book, Microwave-assisted hydrodistillation (MAHD) was used to extract an essential oil from Limograss and Gingger.