Progressive supranuclear palsy (PSP) is a neurologic syndrome of unknown cause. This idiopathic type of PSP is usually associated with characteristic clinical and pathological features.To assess evidence of cerebrovascular disease in a population of patients with clinically defined PSP, and to compare clinical and neuroimaging features in vascular versus idiopathic PSP.Using predetermined criteria, the records of 128 patients diagnosed with PSP were reviewed for evidence of vascular disease.Thirty patients (23.3%) satisfied criteria for vascular PSP. The vascular group differed from the idiopathic group by asymmetric and predominantly lower body involvement (p < 0.05). Corticospinal signs, pseudobulbar signs, gait difficulties, dementia, and incontinence of bowels and bladder were also more common in the vascular group, but these differences did not reach statistical significance.PSP is a syndrome which can be caused by cerebro-vascular disease. In addition to an increased frequency of stroke risk factors and neuroimaging evidence of vascular disease, vascular PSP can be differentiated from idiopathic PSP by a higher degree of asymmetry, lower body involvement, and evidence of corticospinal and pseudobulbar signs.