Homoeopathic Materia Medica contains a large number of drugs of Plant, Chemical and Animal origin, whose standardization is essential to ensure safety, efficacy and quality. It involves identification of exact source materials and other parameters which define pharmaceutical uniformity. Standards of Homoeopathic drugs are drawn on the basis of studies on pharmacognostical, physico-chemical and pharmacological parameters for each drug. The Pharmacognostical studies include macro and microscopical characteristics of raw drugs of vegetable origin. The survival, existence and the potential of a system of medicine solely depends upon the purity, quality, genuineness and the authenticity of the drugs used by the system. Hence, Drug Standardization plays a prime role in the development of the particular system of medicine. The Homoeopathic System of Medicine mainly uses drugs of plant origin. The Central Council for Research in Homoeopathy has conducted Drug Standardizationstudies of more than 200 plants used in the system of Homoeopathic treatment. The present work has been carried out at the four Drug Standardization Centres of the Council viz., Central Research Institute (Homoeopathy), Kolkatta, Homoeopathic Drug Research Institute, Lucknow, Drug Standardization Units at Ghaziabad and Hyderabad, embodying detailed studies of the drugs from pharmacognostical, physicochemical and pharmacological aspects.