Aneurysmal rupture is the main cause of subarachnoid hemorrhage (SAH), leading to neurological and cognitive deficits. The clinical significance of enlarged perivascular spaces (EPVS) on aSAH (aneurysm subarachnoid hemorrhage) outcomes was unclear. Our aim was to explore the association between EPVS and the clinical outcomes of aSAH. Magnetic resonance imaging (MRI) scans of 195 aSAH survivors were analyzed. Poor outcome was defined as modified Rankin Scale (mRS) ≥ 3. Cognitive outcomes were measured with the Montreal Cognitive Assessment (MoCA). We compared the clinical characteristics of aSAH with EPVS < 10 and EPVS ≥ 10 in basal ganglia (BG) and centrum semiovale (CSO) and investigated the association of EPVS severity and topography with delayed cerebral ischemia (DCI), subacute hydrocephalus, and 3-month unfavorable functional outcome and cognitive status using binary logistic regression model, respectively. At 3 months, 159 patients completed the MoCA assessments, and 63 (39.6%) were diagnosed with cognitive impairment (MoCA < 22). BG-EPVS ≥ 10 was associated with unfavorable functional outcomes at 3 months (odds ratio [OR] 2.426, 95% confidence interval [CI] 1.128-5.216, p < 0.05), subacute hydrocephalus (OR 3.789, 95% CI 1.049-13.093, p < 0.05), and DCI (OR 2.579, 95% CI 1.086-6.123, p < 0.05), but not with cognitive impairment after adjusting for established predictors. CSO-EPVS was linked to unfavorable functional outcomes at 3 months (OR 3.411, 95% CI 1.422-8.195, p < 0.05) and worse cognitive function (OR 2.520, 95% CI 1.136-5.589, p < 0.05). Our cohort study reveals that both BG-EPVS and CSO-EPVS are independently associated with unfavorable functional outcomes after aSAH. However, only CSO-EPVS, not BG-EPVS, is related to cognitive impairment at 3 months.© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.