Transmyocardial laser revascularization is currently being tested in randomized clinical trials as an alternative technique for relieving angina in patients with ischemic myocardium. In this technique, an 800-W carbon dioxide laser is used to create channels in the myocardium that open directly into the left ventricular cavity. Although the exact mechanism by which tissue revascularization occurs is not yet known, initial results from an earlier clinical trial were promising: a significant number of patients were relieved of angina symptoms, exercise tolerance was improved, complications were minimal, and the safety of the technique seems established. A controlled, randomized trial is now underway, and initial results appear promising.