Aim: Chromolaena odorata has been used traditionally for the treatment of various conditions which include skin infections, wounds, ulcers and also used as an antimalarial. The present work investigates the ability of the methanolic extract of the plant to inhibit hydrogen-peroxide induced haemolysis and lipid peroxidation of human erythrocytes. Other in vitro antioxidant and free radical scavenging activities were also investigated. Materials and Methods: Dried leaves of Chromolaena odorata were pulverized and extracted using absolute methanol. Venous blood was collected from a healthy individual and erythrocytes isolated. Erythrocyte haemolysis and lipid peroxidation were induced using hydrogen peroxide and subsequently treated with Chromolaena odorata extract. The plant extract was also assessed for its hydrogen peroxide scavenging, hydroxyl radical scavenging and reducing abilities. In all cases, vitamin C was used as the reference compound. Results:The results show that Chromolaena odorata extract reduced hydrogen peroxide-induced haemolysis and lipid peroxidation when compared to vitamin C. While the IC 50 values for the extract were 4.11 mg/mL and 12.95 mg/mL for inhibition of erythrocyte haemolysis and lipid peroxidation respectively, the IC 50 values for vitamin C were 1.98 mg/mL and 0.57 mg/mL for haemolysis and lipid peroxidation. The extract also possessed hydrogen peroxide scavenging, hydroxyl radical scavenging and reducing abilities. In most cases, the effects were concentration-dependent and significant among various extracts concentrations (p < 0.05). Conclusion:The observed responses indicate that the plant possessed immense antioxidant potential which could be ascribed to the bioactive phytochemicals. This could be exploited pharmacologically. ARTICLE HISTORY