The concept of direct revascularization of ischemic myocardium by transmural left ventricular conduits has been investigated by several researchers. Early success was followed by closure of the pathways by fibrosis and scarring caused by mechanical trauma. The CO2 laser was examined as an alternative method of creating channels. Early experiments supported the hypothesis that laser channels would perfuse ischemic areas and would remain patent. Histological examination showed patent, endothelialized channels more than 2 years following operation in the experimental model. A clinical protocol was designed to assess the results of laser revascularization in a series of 12 patients. Patients selected were candidates for bypass grafting, but because of the coronary artery pathology involved, it was thought bypass grafting alone would result in incomplete revascularization. None of the 12 patients have died. Follow-up ranges from 3 to 32 months. Postoperative thallium stress tests and left ventriculography indicate that channels have remained patent and that they perfuse the myocardium. Direct laser revascularization of the myocardium may offer a viable adjunct in the treatment of ischemic heart disease.