The AD8 questionnaire developed by Washington University in St Louis is a screening tool with 8 questions to reliably differentiate nondemented from demented individuals even at the very mild stage. We recruited 239 participants, including 114 cognitively normal, 73 very mild dementia, and 52 mild dementia to validate its application in Taiwanese. The cut-off value of AD8 was 2 in discriminating cognitively normal from demented individuals with the area under curve (AUC) = 0.961, sensitivity = 97.6%, specificity = 78.1%, positive likelihood ratio (PLR) = 4.5, and negative likelihood ratio (NLR) = 0.03. The cut-off value also was 2 in discriminating nondemented from very mild dementia with the AUC = 0.948, sensitivity = 95.9%, specificity = 78.1%, PLR = 4.4, and NLR = 0.05. The Chinese AD8 is effective in discriminating individuals with dementia, even at its mildest stages from those without dementia with properties identical to the original English version. The cAD8 is a quick dementia screening tool that can be applied across cultures.