Background: Aging is associated with decreased penumbral salvage in patients with ischemic stroke. Another critical factor that determines the fate of penumbra tissue is the degree of collateral circulation, which decreases significantly with aging in experimental models of stroke. In this study, we sought to identify whether these observations could be translated to humans and, therefore, analyzed the effect of patient age on extent of leptomeningeal collaterals in patients with ischemic stroke. Methods: Computed tomography angiography (CTA) source images were used to assess the degree of collateral circulation in a retrospective series of patients with proximal middle cerebral artery (MCA) occlusion. Bivariate and multivariate analyses were used to explore the relationship between patient age and degree of collateral circulation. Results: A total of 70 patients were included into the study. Older age (P = .005), history of hypertension (P = .036), higher admission National Institutes of Health Stroke Scale (NIHSS) scores (P = .013), and increased time to CTA (P = .013) were associated with inadequate collaterals in bivariate analyses. In multivariate analysis, older age (P = .008) and higher NIHSS scores (P = .032) remained as the only significant independent variables that were associated with inadequate collaterals. A 10-year increment in patient age increased the odds of inadequate collateral circulation by 1.87 (95% confidence interval: 1.18-2.97). Conclusion: Our findings show that there is a significant interplay between patient age and adequacy of leptomeningeal collateral circulation in patients with proximal MCA occlusion. The relationship could contribute to adverse tissue outcome and thereby to unfavorable clinical outcome observed in elderly patients with ischemic stroke.