Early identification and intervention of cognitive decline could be effective to prevent progression to dementia. We developed a self-delivered cognitive screening tool, Automated Memory and Executive Screening (AMES), to assess cognitive domains including memory, language, and executive function. 189 participants with diagnoses of mild cognitive impairment (MCI, n = 43), subjective cognitive decline (SCD, n = 29), objectively-defined subtle cognitive decline (obj-SCD, n = 18), and normal controls (NC, n = 99) completed the study. AMES had good convergent validity with conventional scales, and was good to discriminate patients with MCI (area under the curve [AUC] = 0.88; sensitivity = 86%; specificity = 80%) and obj-SCD (AUC = 0.78; sensitivity = 89%; specificity = 63%) from NC. These findings support that AMES is an easy to administer and effective instrument to screen for early cognitive impairment in community-based settings.