Lower extremity embolic arterial occlusion is often associated with proximal atherosclerotic and/or aneurysmal disease. Fixed atherosclerotic disease of the abdominal aorta has been demonstrated by ultrasonography, tomographic studies, and aortography, but mobile debris has not previously been described. We report detection of mobile thrombi in the abdominal aorta during transthoracic echocardiography screening in 6 patients with lower extremity embolic arterial occlusion.Six patients were referred to the echocardiography laboratory for evaluation of a source of peripheral arterial embolism. The transthoracic echocardiogram was extended to include longitudinal and transverse images of the abdominal aorta. Additional investigations included abdominal ultrasound (6 patients), computed tomography (2 patients), angiography (2 patients), and transesophageal echocardiography (4 patients).Six patients (4 men, 2 women, aged 46 to 79 years) presented with a blue toe syndrome consistent with atheroembolism. During transthoracic echocardiography with examination of the abdominal aorta, all were found to have significant atherosclerotic disease of the abdominal aorta with one or more mobile components. This finding had a significant impact on treatment of each patient. Surgical resection of the involved portion of the abdominal aorta in one patient demonstrated an ulcerated atheroma with overlying thrombus.In patients with lower extremity embolic arterial occlusion, evaluation of the abdominal aorta during transthoracic echocardiography should be a routine extension of the echocardiographic examination. The finding of mobile thrombi in the abdominal aorta identifies a potential source of embolism for which effective treatment exists.