The present paper describes alterations in the structure of bark, wood and gum-resin canals ofCommiphora mukul in response to mechanical injury. The samples of bark collected after 15 minutes of injury showed signs of visible distortion or collapse of cell walls, specifically of the phloem cells near the gum-resin canals. The process of cell wall degradation gets intensified after 45 minutes of injury and the complete cell collapse is sometimes evident. The histology of healed bark reveals mass dissolution of cells at the site of injury. Several phloem parenchyma cells show structural similarity with the epithelial cells of gum-resin canals. The intercellular spaces show the presence of gum as well as resin droplets. The wall of epithelial cells facing the duct lumen disintegrates and the resultant product is released into the duct lumen. The vessels and axial parenchyma cells close to the site of injury are plugged with gum-resin content. The development of tylosis as a result of injury is also evident in some vessels.