Terminalia arjuna (T.arjuna) bark is extensively used by Indian herbal medicine practitioners for treating various cardiovascular ailments. Though multiple clinical trials and non-clinical studies have been reported on T.arjuna bark, the toxicology data was found to be inadequate. Hence, studies were conducted to establish the toxicology profile of T.arjuna bark. In the acute toxicity study, animals were administered with a single dose of 2000 mg/kg of T. arjuna bark hydroalcoholic extract, whereas in repeated dose toxicity study animals were administered with the extract at doses of 0, 100, 500, and 1000 mg/kg, once daily, for 28 consecutive days, and on day 29, all the animals were humanely sacrificed after the collection of required blood samples. There were no mortality or clinical signs of toxicity observed after administration of a single dose of 2000 mg/kg of T. arjuna bark hydro-alcoholic extract. In the repeated dose toxicity study, there were no treatment-related adverse effects in any of the dose groups and control group animals in respect to clinical signs, body weight, feed consumption, haematology, clinical chemistry, urinalysis, and histopathology. Based on the results, LD50 of T. arjuna bark hydro-alcoholic extract is concluded as >2000 mg/kg. No-Observed-Adverse-effect Level of T. arjuna bark hydroalcoholic extract from 28-day repeated dose toxicity study is established at 1000 mg/kg/day. [ABSTRACT FROM AUTHOR]