Holarrhena antidysenterica R. Br. Sans (Kutaj) belonging to family Apocyanaceae is a small tree or shrub. Its bark is used as an astringent, anthelmintic, stomachic, febrifuge, diuretic, and also useful in piles, dyspepsia, chest infections, amoebic dysentery, and other gastric disorders. Increasing demand and destructive harvesting of bark has led to the depletion of this valuable medicinal tree. A study was conducted to standardize sustainable harvesting practices of stem bark and suitability of alternative plant parts. Different bark harvesting methods were experimented. In these methods tree girth was divided into three or four equal parts and the bark was extracted from one part and harvesting was done by removing longitudinal strips from the main trunk of the tree. Alternate/opposite strips were also experimented in younger/thinner trees. The harvested bark samples and different plant parts like twig bark, wood, flowers and leaves were analysed for tannins, total phenols, total alkaloids and total flavonoids. Phytochemical analysis revealed that the active ingredients in trunk bark were comparatively higher, i.e., total phenols (7.51±0.12%), total flavonoids (0.19±0.09%), total alkaloids (2.25±0.06%), and tannins (8.61±0.10%) than other plant parts studied. Strip harvesting was found to be the best method for harvesting and by this method the bark can be harvested on sustainable basis after every 18 months. Bark should be harvested by removing only outer and middle bark leaving the inner bark for regeneration.