The purpose of this study was to compare the short-term effects of an intensive lifestyle modification (ILM) program on lipid peroxidation and antioxidant systems in patients with coronary artery disease (CAD). Twenty-two patients in the control group continued to receive their conventional treatment with lipid-lowering drugs, whereas 22 patients in the experimental group were assigned to intensive lifestyle modification (ILM) without taking any lipid-lowering agent. The ILM program comprised dietary advice on low-fat diets, high antioxidants and high fiber intakes, yoga exercise, stress management and smoking cessation. After 4 months of intervention, patients in the experimental group revealed a statistically significant increase in plasma total antioxidants, plasma vitamin E and erythrocyte glutathione (GSH) compared to patients in the control group. There was no significant change in plasma malondialdehyde (MDA), a circulating product of lipid peroxidation, in either group. We concluded that the ILM program increased circulating antioxidants and reduced oxidative stress in patients with CAD.