Objectives: Patients with coronary artery disease (CAD) concomitant with extracranial and intracranial atherosclerotic disease (EICAD) may have an increased risk of stroke and myocardial ischemic events. This study aimed to evaluate the concomitant atherosclerotic lesions in extra- and intracranial arterial beds in patients with CAD.Methods: A total of 1274 patients who underwent coronary angiography due to ischemic heart disease were included. All patients underwent ultrasound screening of the extra- and intracranial arteries before coronary angiography, and the degrees of extracranial carotid artery disease (ECAD) and intracranial cerebral artery disease (ICAD) were recorded.Results: A total of 1062 cases of CAD were confirmed. The prevalence of ECAD, ICAD, and EICAD (ECAD combined with ICAD) in patients with CAD was 15.6%, 11.2% and 11.9%, respectively. For patients with 3-vessel disease, the prevalence was 20.5%, 13.8% and 18.1%, and for patients with severe coronary artery stenosis, the prevalence was 15.8%, 12.1% and 13.2%, respectively. The presence and extent of ECAD and ICAD were positively correlated with the number of lesion vessels and degree of CAD. The posterior circulation arteries were more prone to lesions in patients with ECAD, while the anterior circulation arteries were more vulnerable to lesions in patients with ICAD.Conclusions: The prevalence of ECAD, ICAD and EICAD is high in patients with CAD, and the presence of these conditions is positively correlated with the extent and degree of CAD. Evaluations of ECAD and ICAD should be highly recommended for CAD patients to reduce the future risk of cardiovascular diseases.