To assess the feasibility of using transesophageal echocardiography to detect the coronary arteries and blood flow in them, 73 consecutive patients were studied prospectively. A single-plane transducer (5.0 MHz, 64 elements) was employed. Varying lengths of the proximal left anterior descending artery (3 to 30 mm; mean, 10.7±5.5 mm), the circumflex artery (3 to 27 mm; mean, 11.7±5.6 mm), and the right coronary artery (5 to 23 mm; mean, 11.7±4.1 mm) were also visualized in these patients. On the basis of the criteria for detection by TEE established in this study, the left main coronary artery was visualized in 67 (92%) patients, the left anterior descending artery in 46 (63%) patients, the circumflex artery in 61 (84%) patients, and the proximal right coronary artery in 53 (73%) patients. Color Doppler detected coronary blood flow in the left main coronary arteries of 49 (67%) patients, in the left anterior descending arteries of 26 (36%) patients, in the circumflex arteries of 27 (37%) patients, and in the right coronary arteries of 19 (26%) patients. Pulsed-wave Doppler was able to determine velocity of coronary blood flow in the left main coronary arteries of 39 (53%) patients, in the left anterior descending arteries of 22 (30%) patients, in the circumflex arteries of 11 (15%) patients, and in the right coronary arteries of 9 (12%) patients. Abnormal flow pattern just distal to stenosis was observed in 2 (40%) of 5 patients who had angiographic obstruction of≥90% in the left main or the proximal anterior descending coronary artery. Rate of detection of the various coronary arteries, and their blood flow, varied from artery to artery. Results of this study indicate that use of transesophageal echocardiography is feasible for examining the left main coronary artery and the right and left coronary ostium, and further, that transesophageal echocardiography appears to sense abnormal flow associated with presence of significant coronary narrowing in the proximal coronary artery.