To establish a comparative account within the taxa by assessing its anti-oxidative property and mapping it with the morphometric characters. The methanolic leaf extracts of 12 Cassia L. species were screened for their antioxidant activity using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and reducing power capability with reference to standard Ascorbic acid. Chamaecrista kleinii exhibited strong antioxidant activity with IC50 2.17 µg mL-1, followed with Senna auriculata (IC50 11.51 µg mL-1) and Senna polyphylla (15.17 µg mL-1). Highest reducing ability was observed in Senna auriculata extract with 0.676 nm absorbance. The correlation observed between the reducing power and DPPH radical scavenging assay supports the contribution of the phytoconstitutents like phenolics and flavonoids towards managing oxidative stress. The present study reveals the beneficiary effects of the selected plants by virtue of their antioxidant activity that can be harnessed in drug formulations. Keywords: Antioxidant, 1, 1-diphenyl-2-picryl hydrazyl, reducing power, Cassia.