Valerian (Valeriana officinalis) belonging to valerianaceae family is a well-known herb and medicinal plant that has been widely used all over the world especially in Europe, China and Middle East. It is widely used as a sleep aid and sedative in many parts of the world but is also known to relax smooth muscle, hence used for treating  stomach and intestine cramps. Alkaloids, terpenes, organic acids and its derivatives, valepotriates and flavones are the known pharmacologically active compounds found in valerian extract. In general, it is accepted that the valepotriates are the compounds responsible for the sedative activity of the Valerianaceae. The present article aims at reviewing the recent reports on its constituents, traditional use, clinical use and scientific verification of pharmacological actions of valerian.