Background and Aim Cerebral vasospasm (CVS) is one of the main causes of adverse outcomes due to delayed ischemic cerebral infarction in patients with subarachnoid hemorrhage (SAH). The purpose of this study was to explore CVS-related risk factors in elderly patients with SAH, providing a basis for early clinical prediction and therapeutic strategy. Methods Data including demographic factors, healthy habits, history, stress factors, complications and Hunt-Hess grade in acute phase, treatment time, and bleeding-involved encephalic region were collected from 62 elderly patients with SAH, and CVS-related risk factors in elderly patients with SAH were identified with logistic and Cox analyses. Results History of diabetes was a low probability factor of CVS occurrence before and during hospitalization [before hospitalization: odds ratio (OR)=2.258; 95% confidence interval (CI), 0.944-5.398; P=0.067; during hospitalization: OR=1.408; 95% CI, 0.994-1.994; P=0.054)]. Increased WBC count was a predictive factor of CVS occurrence (OR=1.515; 95% CI, 1.045-1.247; P=0.028). Histories of smoking [hazard ratio (HR)=1.044; 95% CI, 1.010-1.078; P=0.010)] and hypertension (HR=1.092; 95% CI, 1.025-1.163; P=0.006) were independent risk factors of CVS occurrence during hospitalization. Prolonged hospital stay decreased CVS occurrence (HR=0.931; 95% CI, 0.878-0.987; P=0.016). Conclusions The incidence of CVS is significantly increased in elderly patients with SAH who have histories of smoking and hypertension and higher WBC count on admission. Prolonged hospital stay can decrease the incidence of CVS.