Memory complaint may be very common in elderly people over 65, but also is present in early stage of dementing processes. Instruments to detect dementia in primary health care must be easy and quickly to be applied. In 2005, Galvin et al. developed a questionnaire Alzheimer's Disease 8 (AD8) which was based on a brief interview with and informant to detect subjects with dementia. The objective of this work was to perform the translation, adaptation to the Spanish language near the Rio de la Plata and to establish the validity, reliability and discriminative proprieties of AD8-arg for use in primary care. Methods 18 patients with dementia of Alzheimer type, 25 with mild cognitive impairment and 19 normal controls matched by age and education were assessed with the AD8-arg and an extensive neuropsychological battery. Concurrent validity was strong with significant correlation with MMSE (-0,464: P<0.001) and CDR (0,514; P<0.001). Internal consistency was adequate correlating with all cognitive tests. The area under the ROC curve was 0.89 and a cutoff score of 2 had a sensitivity of 0.80 and specificity of 0.83 showing excellent discrimination between demented and non-demented patients. The AD8-arg is a tool for quick and easy administration with adequate psychometric properties for use in screening of dementia in primary care in our region.