Objective: To investigate whether the topography of dilated perivascular spaces (DPVS) corresponds with markers of particular small-vessel diseases such as cerebral amyloid angiopathy and hypertensive vasculopathy. Methods: Patients were recruited from an ongoing single-center prospective longitudinal cohort study of patients evaluated in a memory clinic. All patients underwent structural, high-resolution MRI, and had a clinical assessment performed within 1 year of scan. DPVS were rated in basal ganglia (BG-DPVS) and white matter (WM-DPVS) on T1 sequences, using an established 4-point semiquantitative score. DPVS degree was classified as high (score > 2) or low (score ≤ 2). Independent risk factors for high degree of BG-DPVS and WM-DPVS were investigated. Results: Eighty-nine patients were included (mean age 72.7 ± 9.9 years, 57% female). High degree of WM-DPVS was more frequent than low degree in patients with presence of strictly lobar microbleeds (45.5% vs 28.4% of subjects). High BG-DPVS degree was associated with older age, hypertension, and higher white matter hyperintensity volumes. In multivariate analysis, increased lobar microbleed count was an independent predictor of high degree of WM-DPVS (odds ratio [OR] 1.53 [95% confidence interval (CI) 1.06-2.21], p = 0.02). By contrast, hypertension was an independent predictor of high degree of BG-DPVS (OR 9.4 [95% CI 1-85.2], p = 0.04). Conclusions: The associations of WM-DPVS with lobar microbleeds and BG-DPVS with hypertension raise the possibility that the distribution of DPVS may indicate the presence of underlying small-vessel diseases such as cerebral amyloid angiopathy and hypertensive vasculopathy in patients with cognitive impairment. © 2013 American Academy of Neurology.