Coronary artery stenosis (CAS) ≥ 50% frequently coexists in patients with acute ischemic cerebrovascular disease (AICVD), which portends unfavorable outcomes. We sought to examine whether patients with AICVD with CAS had more severe and more diffused cervicocephalic atherosclerosis (CA). Patients with AICVD were consecutively enrolled and underwent simultaneous computed tomography angiography (CTA) of the coronary and cervicocephalic arteries. A total of 140 patients were divided into "AICVD＋CAS" and "AICVD only" groups according to whether CTA showed stenosis of ≥ 50% in at least one coronary arterial segment. The relationship of the presence of CAS with the severity and extent of CA were examined. The CA severity characteristics, including the presence of stenosis ≥ 50% and the grade of the most severe stenotic segment, were not significantly different between the two groups. Regarding the extent of CA, the presence of stenosis ≥ 50% in both sides (adjusted odds ratio [OR]: 4.29, 95% confidence interval [CI]: 1.67-10.98), both extracranial and intracranial (adjusted OR: 5.26, 95% CI: 2.24-12.35), both anterior and posterior circulation (adjusted OR: 5.29, 95% CI: 2.22-12.64), and the number of stenotic segments ≥ 50% in cervicocephalic arteries (adjusted OR: 1.58, 95% CI: 1.28-1.96) were associated with CAS in patients with AICVD, independently of clinical demographics and CA severity characteristics. CA was similarly severe in patients with AICVD with and without CAS, but those with CAS had significantly more diffused CA. The extent of CA and CAS were mutual indicators in patients with AICVD, irrespective of CA severity.