Background Mechanical thrombectomy is an effective treatment method for large‐vessel occlusion stroke (LVOS); however, it has limited efficacy for intracranial atherosclerotic disease (ICAD)‐related LVOS. We investigated the use of cerebral blood volume (CBV) maps for identifying ICAD as the underlying cause of LVOS before the initiation of endovascular treatment (EVT). Methods and Results We reviewed clinical and imaging data from patients who presented with LVOS and underwent endovascular treatment between January 2011 and May 2021. The CBV patterns were analyzed to identify an increase in CBV within the hypoperfused area and estimate infarct patterns within the area of decreased CBV. Comparisons were made between the patients with an increase in CBV and those without, and among the estimated infarct patterns: territorial, cortical wedge, basal ganglia–only, subcortical, and normal CBV. Overall, 243 patients were included. CBV increase in the hypoperfused area was observed in 23.5% of patients. A significantly higher proportion of ICAD was observed in those with increased CBV than in those without (56.4% versus 19.8%; P <0.001). Regarding the estimated infarct patterns on the CBV, ICAD was most frequently observed in the normal CBV group (territorial, 14.9%; cortical wedge, 10.0%; basal ganglia–only, 43.8%; subcortical, 35.7%; normal, 61.7%). CBV parameters, including “an increase in CBV,” “normal CBV infarct pattern,” and “an increase in CBV or normal CBV infarct pattern composite,” were independently associated with ICAD. Conclusions An increased CBV or normal CBV pattern may be associated with ICAD LVOS on the pretreatment perfusion imaging.