Background/Aims: The Mini-Addenbrooke’s Cognitive Examination (MACE) is a relatively new short cognitive screening instrument for the detection of patients with dementia and mild cognitive impairment (MCI). Few studies of the MACE have been reported hitherto. The aim of this study was to undertake a pragmatic diagnostic test accuracy study of MACE in a large cohort of patients seen in a dedicated cognitive disorders clinic. Methods: MACE was administered to consecutive patients referred to a neurology-led Cognitive Function Clinic over the course of 3 years to assess its performance for the diagnosis of dementia and MCI using various test metrics. Results: In a cohort of 599 patients, the prevalence of dementia and MCI by criterion diagnosis was 0.17 and 0.29, respectively. MACE had a high sensitivity (> 0.9) and negative predictive values (> 0.8) with large effect sizes (Cohen’s d > 1) for the diagnosis of both dementia and MCI but a low specificity (< 0.5) and positive predictive values (≤0.5). Conclusion: MACE is an acceptable test for the assessment of cognitive complaints in a secondary care setting with good metrics for identifying cases of both dementia and MCI.