The rhizome of Acorus calamus Linn. is commonly known as "Vacha" in indigenous systems of medicine. It is distributed in marshy tracts of Kashmir, Sirmaur (Himachal Pradesh), Manipur and the Naga hills. It is regularly cultivated in Koratagere Taluk in Karnataka and other parts of India. This study deals with the detailed pharmacognostical evaluation of the dried rhizomes of Acorus calamus collected from DehraDun (Uttaranchal), Lucknow (Uttar Pradesh). The commercial sample procured from Delhi market was also evaluated to observe the difference between collected and market samples. Dried rhizome is vertically compressed, pale yellow to dark brown and occasionally orangish brown in colour. Transverse section showed two distinct region with scattered, concentric vascular bundles surrounded by fibrous bundle sheath. Some vascular bundles just beneath the endodermis devoid of bundle sheath. Though the botanical and physico-chemical characters of all the samples were quite similar but some variations were observed in High Performance Thin Layer Chromatography (HPTLC) fingerprint profile, the essential oil content and total percentage of asarone which was found to be highest in Lucknow and lowest in Delhi market sample. These variations may be explained due to some edaphic factors or storage conditions. An attempt was also made to test antioxidant activity (in vitro) and it was found to be 88% at 0.2 g/ml concentration.