Until today, a routinely applicable method is not available for intraoperative imaging of the coronary vessels. Our experience with the first 23 patients is discussed to show whether high-frequency echocardiography (HFE) is able to close this gap and to image the coronary arteries intraoperatively in a manner which can be evaluated. After thoracotomy and connecting the heart-lung machine as well as insertion of a transatrial left ventricular vent, ultrasonography was carried out with a 12 MHz linear scanner with a water prerun in the LAD in all cases, and also in the RCA and circumflex branch in 12 cases using sterile ultrasound gel on the fibrillating heart. The results proved that the method is able to image the coronary arteries with good resolution in the transverse section and in the longitudinal course. HFE can be used in particular to locate the intramyocardial course of coronary vessels and in reoperations, for localization of stenoses and occlusions, for determination of optimal sites for anastomoses, for measuring of vessel diameter and degree of stenosis, and for imaging of anastomoses. It will be possible in the future to image and to check intraoperative dilatation and laser angioplasty with HFE.