To study the clinical features of leuko-araiosis. Age matched groups of patients with a CT finding of pure leukoaraiosis (n = 26) and a control group with a normal CT finding (n = 26) were formed (mean ages 78.6 (SD 3.3) v 76.5 (SD 4.6) years; NS). Dementia, vascular dementia, central brain atrophy on CT, disability in activities of daily living and instrumental activities of daily living, urinary incontinence, gait disorder (assistance needed), personality change, and night time confusion were found to be more commonly present in leuko-araiosis positive patients than in controls, whereas focal neurological symptoms and signs were not associated with leuko-araiosis. The occurrences of heart failure and systolic hypotension-but not hypertension-were higher in the leuko-araiosis positive group than in the controls. Leuko-araiosis was also found to be related to a less sudden onset of symptoms and a lower Hachinski score than true brain infarction(s). Leuko-araiosis on CT in these elderly patients seems to be a vascular disorder aetiologically different from brain infarction, with clinical manifestations of subtle onset and general disabling nature and no prominent focal neurological signs or symptoms.