ObjectiveWe aimed to investigate the relationship between intracranial arterial dolichoectasia (IADE) and intracranial atherosclerosis (ICAS). MethodsPatients with acute ischemic stroke were screened via the Nanjing Stroke Registry Program. Patients were diagnosed with IADE (diameter, height of bifurcation, and laterality of basilar artery) based on magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) results. Intracranial atherosclerosis was defined as a ≥50 % diameter reduction in internal carotid artery, middle cerebral artery, posterior cerebral artery, or anterior cerebral artery on MRA, computed tomography angiography, or digital subtraction angiography. We also evaluated the presence and degree of white matter changes and lacuna infarctions on MRI. ResultsOf the 469 enrolled patients, 61 (13 %) had IADE. Patients with IADE were older (64.1 ± 9.9 vs. 59.6 ± 11.4 years, P = 0.004) and had a higher prevalence of hypertension (78.7 % vs. 61.0 %, P = 0.008) than patients without IADE. Patients with ICAS were older (62.6±10.5 vs 58.1±11.6 years, P < 0.001), had higher prevalence of hypertension (72.9 % vs. 55.0 %, P < 0.001) and a previous history of stroke (21.6 % vs. 9.2 %, P < 0.001), had higher levels of serum low-density lipoprotein cholesterol (2.57±0.82 vs. 2.31±0.86mmol/l P = 0.002), and had high counts of white blood cells (7.90±3.29 vs 7.10±2.44, P = 0.004). No association was detected between IADE and extracranial carotid atherosclerosis [odds ratio (OR)=0.618; 95 % confidence interval (CI), 0.280–1.367; P = 0.235]. After adjusting for age, sex, hypertension, and ischemic heart disease, patients with IADE had a lower ICAS rate than that in those without IADE (OR 0.417, 95 % CI, 0.213–0.816, P = 0.011). Unlike patients with ICAS, patients with IADE were more likely to have infratentorial stroke lesions (OR=2.952, 95 % CI, 1.207–7.223, P = 0.018), multi-lacuna (OR=2.142, 95 % CI, 1.158–3.964, P = 0.015), and white matter changes (OR = 2.782; 95 % CI, 1.522–5.085, P = 0.001). ConclusionsIADE was associated with advanced age, hypertension, multi-lacuna, and white matter changes but was not associated with ICAS.