Early diagnosis of a dementia disorder is required for early support, treatment and information. A basic programme including history taking, somatic and neurological examination, blood screening and a structural scan will suffice in typical cases. For patients with uncertain or atypical symptoms or disease course, supplementary investigations are warranted, including biomarkers in cerebrospinal fluid, functional imaging and neuropsychological testing. Also, imaging of specific protein accumulations in Alzheimer's disease may serve to monitor disease progression and effects of interventions.