Herein, we present a case of amaurosis fugax in a 76-year-old female with high blood pressure, dyslipidemia, and chronic atrial fibrillation who frequently suffered from transient visual impairment of the left eye. Color Doppler imaging of the flow profile in the left ophthalmic artery and the left common carotid artery revealed stenosis in the proximal portion of the left common carotid artery. Aortography revealed severe stenosis of the left common carotid artery at its orifice. The left external carotid artery was not observed as no collateral circulation from the left external carotid artery to the left ophthalmic artery was present. The presence of severe stenosis of the left common carotid artery at its orifice was considered to have caused the amaurosis fugax of the left eye, due to a reduction in the blood supply from both the left external carotid artery and the left internal carotid artery. Percutaneous transluminal angioplasty with stenting was successfully performed to dilate the stenosis at the orifice of the left common carotid artery with the aim of restoring visual function by improving the blood supply to the left ophthalmic artery. After stenting, angiography of the left common carotid artery showed improved blood supply in the left ophthalmic artery. The patient was followed up for 2 years after CAS, and no recurrence of amaurosis fugax or rubeosis iridis were observed. In this case, color Doppler imaging was useful for diagnosing and evaluating flow dynamics.