Essential oils are industrially important natural products of aromatic plants, which are biosynthesized in specialized cells types, such as osmophores, Glandular Trichomes, and ducts and cavities, present on different parts of these plants. In these cells, the essential oils are biosynthesized, accumulated and transferred to the atmosphere by different reported secretion mechanisms. Numerous environmental factors also affect biosynthesis of essential oils and their secretion in the atmosphere. A deep understanding of the entire process is important to improve the yield of biomass of aromatic plants and thus produce large quantities of commercial volatile oils. In this paper, the recent research on types and structure of essential oil-bearing cells, secretion mechanisms, and effect of different environmental factors on essential oil biosynthesis have been comprehensively reviewed. Therefore, this review article will provide new research directions for the researchers working in the field of aromatic plants physiology, essential oil production and many others applications.