Few studies have examined the relationship between cerebrovascular disease, vascular risk factors and Parkinson disease (PD), although one study found small vessel disease (SVD) to be the main subtype of cerebrovascular disease. In this study we compared the extent and topography of SVD and assessed associated vascular risk factors in autopsy-proven PD cases and community-dwelling controls . 77 PD and 32 control brains from the Sydney Brain Bank were assessed microscopically by a single examiner blinded to the diagnosis. SVD was assessed by grading perivascular pallor, gliosis, hyaline thickening and enlargement of perivascular spaces in the white matter underlying the superior frontal and primary motor cortices, basal ganglia and white matter tracts. A history of vascular risk factors (hypertension, heart disease, diabetes and cigarette smoking) was obtained. Groups were compared using stepwise multiple regression analysis. There was significantly greater frontal pallor (p=0.004) and widening of perivascular spaces in the globus pallidus interna (p=0.007) in controls compared with PD. Hyaline thickening and widening of perivascular spaces in the frontal white matter, hyaline thickening in the motor white matter and widening of perivascular spaces in the caudate nucleus were more common in the control group, but did not reach significance. The prevalence of vascular risk factors and SVD pathology was significantly lower in autopsy-proven PD compared with controls (p=0.03) living in the same community. The results of this study support the need for further research in this area.