Natural products have played an exceptionally important role in health care and prevention of diseases for thousands of years and are one of the greatest sources of medicine. Mizoram is a home to a rich variety of flora and fauna however; very less systematic survey and documentation were carried out to date. The plant diversity of Mizoram is not adequately studied as compared to other states of north east India. Dillenia pentagyna Roxb., known as kaihzawl in Mizo and dog teak in English, is one of the endangered plants that is yet to be explore. The Mizo communities use the decoction of D. pentagyna bark to treat different stomach ailments, inflammation and diabetes. In this perspective, the methanolic extract of the bark of D. pentagyna was evaluated for its anti-inflammatory properties. The extract showed the presence of flavanoids, triterpenoids, steroids, phenolics, saponins, fixed oils and others exerting varied pharmacological activities. The methanolic extract of this plant was found to contain active constituents such as betulinic acid and β-sitosterol which are found to actively interact with the inflammatory mediators and suppressed the inflammation when evaluated for its in vitro and in vivo anti-inflammatory activity. The present study suggests that the methanolic extract of D. pentagyna bark showed significant anti-inflammatory activity. This study also support the folkloric used of the plant in diseases related to inflammatory condition.