OBJECTIVES: Seoul-Activities of Daily Living(S-ADL) was developed to assess elderly person's basic activities of daily living. This study aims to develop standardized ADL assessment scale and confirm the reliability and validity of the S-ADL. METHODS: It was participated in 336 controls and 145 patients diagnosed Alzheimer's disease. RESULTS: In controls, it was statistically significant to age, but not sex, education, region and presence of spouse. Also, reliability and validity were statistically significant. Principal axis factoring analysis revealed three factors that accounted for 66.67% of the total variance(1.self-care/hygiene, 2.ambulation, 3.toileting). According to each CDR stage, there were significant difference, except for CDR 0.5 and CDR 1 suggesting early dementia. Particularly, it was remarkable for functional impairment in CDR 2 and CDR 3 suggesting moderate to severe dementia. The order of the loss of function was (1) self-care/hygiene, (2) toileting, and (3) ambulation. CONCLUSIONS: Our study showed that the S-ADL could be a very reliable and valid tool for the assessment of functional disabilities of Korean dementia patients. Particularly, S-ADL would be useful in assessing daily function of moderate to severe AD.