The present study aimed to compare antioxidant activities, total phenolic and flavonoid content present in leaves and bark of Terminalia arjuna and check whether there is any correlation between phenolic content and flavonoid content with antioxidant activities or not. Phytochemical screening of ethanolic extract of leaves and bark revealed the presence of phenols, flavonoids, tannins, carbohydrates, glycosides, saponin, phytosterols and phytosteroids. Total phenolic content was found to be higher in bark (272.71±3.18 mg/g gallic acid equivalents) as compared to that of leaves (95±3.11 mg/g gallic acid equivalents). Similarly, flavonoid content of ethanolic extract of bark was found to be higher (203.95±5.13 mg/g rutin equivalents) than that of leaves (87.625±4.28 mg/g rutin equivalents). DPPH activity of ethanolic extract of bark (IC50-17.41 µg/ml) was more than that of leaves (IC50-20.22µg/ml). FRAP activity of bark (IC50- 4.781 µM Fe (II) equivalents) is more than that of leaves (IC50-7.572 µM Fe (II) equivalents). Nitric oxide (NO) scavenging activity of bark (IC50-12.87 µg/ml) was higher than that of leaves (IC50-13.91 µg/ml).The present study clearly showed that there is a correlation between total phenolics, flavonoid contents and antioxidant activity of leaves and bark of T. arjuna. The phenolic compounds and flavonoids could be major contributor to antioxidant activity of T. arjuna. Keywords: Terminalia arjuna, DPPH, FRAP, NO, IC50, Antioxidants