Assessment of frequently enlarged perivascular space (EPVS) is essential for assessing Alzheimer’s disease (AD) patients. Recently, EPVS density has been found to be related to the early diagnosis of mild cognitive impairment. However, characteristics of the EPVS density in AD patients are not well understood. We evaluated 44 AD patients and 40 controls by assessing the frequency and density of EPVS in quantitative and semi-quantitative methods. The density and frequency of EPVS is higher in AD patients than that in controls. These results suggest that EPVS density could be used as an indicator in the assessment of EPVS in AD.