We describe a 68-year-old man with acute stroke in whom the newly developed single sweep method for three-dimensional (3D) carotid ultrasound provided a rapid and comprehensive assessment of atherosclerotic plaque burden in the internal carotid artery. The two-dimensional duplex carotid scan diagnosed 50–69% stenosis, and with the three-dimensional method, the markedly hypoechogenic plaque (total volume 1.42 mL) was shown to occupy 77% of the total arterial volume (1.84 mL), consistent with severe lesion. The ultrasound findings were confirmed by computed tomographic angiography and subsequent carotid endarterectomy. The new single sweep 3D carotid ultrasound has the potential to become a valuable clinical tool in the assessment of stroke patients. (Echocardiography 2013;30:414-418).