Abstract: Garcinia indica have been used for centuries with claim for its medicinal value by traditional practitioners to treat numerous diseases. The anti-oxidant activity of G. indica fruit which were assessed by determining the total phenolic content, evaluating the 2, 2-diphenyl-1-picrylhydrazyl, (DPPH) activity, superoxide dismutase (SOD) activity, as well as its ability to inhibit Nitric Oxide (NO) and also their effect on H2O2 induced Reactive Oxygen Species (ROS) generation in human monocytic (THP-1) cells was investigated by tracking intensity of a cell permeable fluorescent dye. In addition, High Performance Liquid Chromatography (HPLC) was used to quantify the bioactive constituent of G. indica fruit extract responsible for its biological activity. The fruit extract of G. indica had the highest amount of hydroxycitric acid (HCA) and phenolic content showed potent antioxidant activity. The IC50 values for DPPH, SOD and NO scavenging activities were 50.34, 37.08 and 34.15 μg mL–1, respectively. Garcinia indica fruit extract (200 μg mL–1) attenuated ≥60% of H2O2 mediated ROS generation in THP-1 cells. The above data provides evidence that the fruit extract of G. indica is rich in natural anti-oxidants and thus justify its use in folk medicine especially in the management of free radical-mediated disorders.