In present study hydroalcoholic extract of the leaves of plant Casearia tomentosa was investigated for the phytochemical screening, total phenolic content and antioxidant activity.The preliminary phytochemical investigation of leaves extract revealed the presence of active phytoconstituents such as alkaloids, glycosides, steroids, saponins, flavonoids, terpenoids and tannins etc.Total phenolic content was evaluated by Folin-Ciocalteau method which revealed the presence of very good amount of phenolic content (170 mg GAE/g of dry weight) in extract. The extract was also analyzed for antioxidant activity by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing antioxidant potential(FRAP) assay. In vitro DPPH radical scavenging assay showed potent antioxidant power with IC50 values of 60 μg mL-1and Ferric reducing antioxidant power for extract(43.12 μM/ml, FRAP value =2.1) which arecomparable toascorbic acid. The present study reveals that Casearia tomentosa can be used as a potential source of natural antioxidant which may be treat various oxidative stress related diseases.