This book provides clinicians with a theoretically motivated guide to the assessment of patients with cognitive complaints. Its main goal is to teach physicians, psychiatrists, and psychologists how to assess cognition in the clinic or at the bedside based around the instrument, the Addenbrooke’s Cognitive Examination (ACE), developed in Cambridge over many years and subsequently refined and modified. The latest version is the ACE-III, which is freely available and has been translated into many languages. The early chapters provide a framework in which aspects of cognition are considered as those with a distributed representation in the brain (such as attention and memory) versus those with more focal representation (such as language, praxis, and spatial abilities). There are descriptions of the major syndromes encountered in clinical practice, notably delirium and dementia, which have been updated to incorporate recent discoveries. There follows the all-important section on history taking and the ‘meat of the book’: how to perform bedside cognitive testing. The ACE-III is contrasted to other commonly used brief standardized mental test schedules (such as the Montreal Cognitive Examination). Sixteen cases with a full range of cognitive disorders illustrate the method recommended. Finally, there is an appendix outlining the range of formal tests commonly used in neuropsychological practice.