Oxidative stress has been associated with degenerative diseases such as cardiovascular and neurodegenerative diseases. Acute myocardial infarction (AMI) is the major cause of death among cardiovascular diseases. Inflammation, a major risk factor of AMI, is associated with leukocytic activation, secretion of myeloperoxidase (MPO) and subsequent oxidant generation. It has been hypothesized that oxidative stress is a risk factor for AMI. To test this hypothesis, we studied profiles of oxidative damage and antioxidants in patients with AMI. The levels of MPO, 8-OHdG, and 3-Cl-Tyr were higher in blood specimens from AMI patients than in those of controls. Antioxidant levels, such as vitamin E and glutathione peroxidase, were significantly lower in these patients. The GSH/GSSG ratio, indicative of redox status, was also lower in AMI patients. Such findings suggest that these AMI patients experience increased oxidative stress. Moreover, markers in combination are better for evaluating antioxidant status and monitoring cardiac events than the same markers used separately.