Objective: Chronic obstructive pulmonary disease (COPD) has been associated with several complications and mortality in acutely ill patients. For patients with aneurysmal subarachnoid hemorrhage (aSAH), the association between COPD and clinical outcomes remains unclear. Methods: In this retrospective cohort study, we analyzed consecutive aSAH patients admitted to the West China Hospital between 2009 and 2019. Propensity score matching was performed to obtain the adjusted odds ratios (ORs) with 95% CI. The primary outcome was in hospital mortality.Results: Using a ten-year clinical database from a large university medical center, 5643 patients with aSAH were identified, of whom 377 (7.9%) also had COPD. After matching, 289 patients were included in COPD group and 1156 in non-COPD groups. COPD was associated with increased in-hospital mortality (OR 1.63, 95% CI 1.02-2.62) and poor functional outcome at discharge (OR 1.37, 95% CI 1.04-1.80). Similarly, patients with COPD had significantly longer length of hospital stay, higher odds of seizure (OR 2.05, 95% CI 1.04-4.04), pneumonia (OR 3.10, 95% CI 2.38-4.04), intracranial infection (OR 1.62, 95% CI 1.14-2.29), urinary tract infection (OR 1.59, 95% CI 1.16-2.20) and bloodstream infection(OR 3.27, 95% CI 1.74-6.15). Conclusions: Among aSAH patients, COPD is associated with increased mortality. COPD represents a significant risk factor for pneumonia and seizure.