Abstract Background. The presence of ascending aortic atheroma is a known risk for systemic emboli or early saphenous vein graft failure if unrecognized at the time of cardiopulmonary bypass. Methods. This study prospectively compared intraoperative omniplane transesophageal echocardiography (TEE) and epiaortic ultrasound (EAU) images in 22 patients (6 women, 16 men, age 66 ± 8 years) before surgical manipulation of the ascending aorta. Atheroma lesion severity was scored: 1 = normal, 2 = nonprotruding intimal thickening (> 2 mm), 3 = atheroma less than 4 mm ± Ca++, 4 = atheroma greater than or equal to 4 mm ± Ca++, and 5 = any size mobile or ulcerated lesion ± Ca++. The ascending aorta between the aortic valve and innominate artery was divided into proximal, middle, and distal segments. A total of 66 segments were evaluated. Results. Although the overall agreement of scores between procedures was 75.8%, significantly more lesions were identified by EAU (15) than by TEE (5) ( p < 0.03). TEE failed to identify lesions in the middle and distal segments of the aorta with a score of more than 3. Conclusions. Although atheromatous lesions were identified in the ascending aorta by both ultrasound modalities, the results suggest that intraoperative EAU may have an advantage over TEE for surgeons assessing target sites for surgical procedures involving the ascending aorta.