The validity of a computed tomography (CT)-based rating scale that separately rates leukoaraiosis, patchy lesions, and lacunes was tested using neuropathological findings collected on 87 subjects enrolled in the Oxford Project to Investigate Memory and Ageing. The CT-based score (range 0-64) was associated with both small vessel disease (p = 0.015) and microinfarcts (p = 0.002) on pathology. A sum score of subcortical cerebrovascular disease (CVD) on pathology was computed, 0 indicating absent/mild small vessel CVD and no microinfarcts, 1 moderate small vessel CVD or microinfarcts, and 2 and higher both conditions or severe small vessel CVD. Subjects with a sum score of 0 were decreasing with increasing severity of CT-based score (64, 46, and 25% in those with CT-based scores of 0, 1-38, and 39 and higher), while those with a sum score of 2 and higher were increasing (0, 14, and 44%; p = 0.002). A standardized assessment of subcortical CVD on CT films can be compounded into a unique score that is in good agreement with neuropathology. This supports the validity of the CT-based visual rating scale as a valid tool to detect subcortical vascular changes in elderly persons.