A diagnosis of dementia should be made only after comprehensive assessment, which inevitably includes history taking, cognitive and mental state examination, physical examination, a review of medication in order to identify and minimize use of drugs that may adversely affect cognitive functioning, and other appropriate investigations. Clinical cognitive assessment in those with suspected dementia should include examination of attention and concentration, orientation, short- and long-term memory, praxis, language and executive function. As part of this assessment, formal cognitive testing should be undertaken using a standardized instrument. Formal neuropsychological testing should form part of the assessment in cases of mild or questionable dementia.