While angiography remains the standard evaluation method for the visualisation of coronary artery anatomy and morphology, the angiographic findings in patients referred for surgical treatment of coronary artery disease (CAD) often do not totally answer questions related to surgical management. We therefore explored a high-frequency ultrasonic technique that allows the surgeon to localize coronary artery lesions not demonstrated angiographically, such as the distribution of coronary artery calcification in myocardial vessels buried in fat or obscured by epicardial scarring frequently observed in patients who had previously been operated upon. Coronary arteries of 81 patients were investigated intraoperatively. Stenotic arteriosclerotic or fibrotic lesions of the arterial wall could be easily seen. This technique provides additional information to preoperative angiograms, especially in locating major coronary arteries that lie intramyocardially, or those deeply buried in fat. Intraoperative coronary artery dilatation procedures could be followed and the effects determined by measuring pre- and postoperative diameters.