Hydnocarpus is a genus of flowering plant, commonly called chaulmoogra, belonging to the family Achariaceae. The folklore claims the use of the whole plant for curing various ailments. The oil extracted from seeds of Hydnocarpus pentandrus (Buch-Ham.) Oken. contains secondary metabolites such as glycosides, carbohydrates, proteins, tannins, saponins etc. The leaves are used for cardiac problems, hepatic problems, otalgia, and eruptions. Standardization is an essential measure for quality, purity & sample identification. Anatomy is very useful in the study of plant materials. Macroscopic characters, along with microscopy is one of the simplest & cheapest methods to start with for establishing and correct identity of the source materials. In the present study the sections of leaf, petiole & stem, leaf architecture, types of stomata, stomatal frequency, stomatal index of the leaf of Hydnocarpus pentandrus was undertaken. It showed pinnate camptodromous with festooned brochidodromous type of venation and anomocytic type of stomata. This study will be helpful in correctly identifying the plant materials which are of medicinal importance.