The present study was conducted to elucidate the antioxidant role of garlic oil in isoproterenol (IPL)-induced myocardial infarction in rats. In myocardial necrosis induced by isoproterenol, a significant increase in serum iron content with a significant decrease in plasma iron binding capacity, ceruloplasmin activity and glutathione (GSH) level were observed. There was also a significant increase in lipid peroxides levels on isoproterenol administration. Activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and glutathione reductase (GRD) were decreased significantly in heart with isoproterenol-induced myocardial necrosis. Garlic oil produced a marked reversal of these metabolic changes related to myocardial infarction induced by isoproterenol. In conclusion, garlic oil exerts its effects by modulating lipid peroxidation and enhancing antioxidant and detoxifying enzyme systems.