The antioxidant activity of the M. peregrina leaves was investigated by two in vitro models of screening, namely, DPPH and H2O2 free radical scavenging method. DPPH and H2O2 radical scavenging activity of various crude extracts was compared with standard ascorbic acid. During the DPPH free radical reaction, the degree of discoloration (decrease in absorbance) of the DPPH solution indicates the scavenging potentials of the sample antioxidant. The crude extracts of M. peregrina contain plant secondary metabolites such as alkaloids, tannins, saponins, glycosides, etc. All these bioactive compounds have the ability to discolor DPPH solution by their hydrogen donating ability[24]. The results of antioxidant activity of the extracts expressed in percentage DPPH activities are presented in this study. All the four extracts exhibited high antioxidant activities comparable to ascorbic acid in concentration dependent manner and maximum activity was observed at 200 μg/mL. Methanol extract exhibited the highest antioxidant activity among all extracts and no statistically significant difference was noted between it and ascorbic acid IC50 value. Surprisingly, hexane extract which did not reveal the presence of phenolics also exhibited good free radical scavenging activity, suggesting that hexane extracts contain some non phenolic constituents which are responsible for its antioxidant activity. The antioxidant activity of M. peregrina leaves was found to be better than that of M. oleifera flowers and stem, the most commonly used species of genus Moringa in tropical and subtropical countries for various ailments[14,25]. However, leaves extract of M. oleifera showed significant antioxidant activity against DPPH radical and similar to previously reported results for M. oleifera leaves, but no correlation between antioxidant activity and TPC was observed for M. peregrina leaves.