Synopsis Man's interest in plants in mainly for food and medicines. The history of herbal medicine is as old as human civilization. In the past, almost all the medicines were used from the plants, the plant being man's only chemist for ages. Drugs are chemical substances, which by interacting with biological systems change their behaviour, which is used for the purpose of diagnosis, prevention, relief or cure of a disease in man or animals. Since his existence on this planet, man has had to depend on nature for substance and survival. He used medicinal plants to keep himself healthy. According to the studies on ethnomedicine and folk medicine about 2000 species are newly identified as drug yielding plants and are well known for their use in about 4000 drug industries of various Indian system of medicine. Phytochemical examination of a number of them has been carried out and active ingredients isolated, identified are being currently used as drugs. Drugs such as aspirin, codeine, pitocarpine, quinine, reserpine, sceopolamine, theophylline, vinblastine and taxol are but a handful that had come from ethnobotanical findings. Chemical examination of hitherto unexplored medicinal plants will help in discovering new drugs.