primary neurodegenerative dementia, and vascular mild cognitive impairment (vMCI). We investigated the prevalence of VCI and its subtypes in a Korean elderly population.Methods: This study was a part of the Korean Longitudinal Study on Health and Aging (KLoSHA) which had been conducted on the residents aged 65 years or older in Seongnam, Korea from September 2005 to August 2006. A simple random sample (N1⁄41118) was drawn from the roster of 61,730 persons aged 65 years or older. Standardized clinical interviews, neurological and physical examinations and comprehensive neuropsychological assessments were administered. Diagnosis of vascular dementia was made according to NINDS-AIREN criteria. Diagnosis of mixed dementia was made according to DSM-IV-TR criteria. And, diagnosis of vMCI was made according to the MCI criteria proposed by the InternationalWorking Groupwith vascular risk factors (Modified Hachinski ischemic scale 4). Results: Ageand sex-standardized prevalence rate of VCI was 4.4% (95% CI1⁄42.9%-5.9%). Ageand sex-standardized prevalence of VD or mixed dementia was 1.4% (95% CI1⁄40.6%-2.3%), and that of vMCI was 3.0% (95% CI1⁄41.8%-4.3%). The prevalence of VCI increased with advancing age (2.3% in 65-69, 5.1% in 70-74, and 6.8% in 75 or older). Gender and educational level had no significant influence on the prevalence of VCI. Conclusions: The prevalence of VCI in Korean elders was comparable to other western countries (5% in Canada, 6.6% inUK) and older age was significantly associated with an increased risk of developing VCI. As operational criteria of VCI is still variable between studies, it is warranted to establish uniform operational criteria for VCI for ensuring validity and comparability in future researches.