This handbook contains the brief information on medicinal plants mainly used in Indian systems of medicine. Nearly 1000 plant species belonging to 164 families either used as main sources of the drugs or as their substitutes and adulterates are given in it. The drug plants have been given family-wise following the Bentham and Hooker's system of classification. The brief information about the drug plants i.e. Names (Sanskrit and Botanical) habit of the plants, part (s) used in medicine, main properties/uses and broadly the name of area (s) where the plants naturally occur has been given in tabular form. The names of common substitutes and adulterants of important drug plants have also been provided. Indexes of botanical and Sanskrit names are also given.