From today's point of view, patients with a mild cognitive impairment (MCI) are at risk for developing a dementia. This clinical picture occurs frequently in the population and is easily recognized through simple tests and interviews conducted in the general and neurological medical practice. A goal of the diagnostics is to detect potentially redressable causes, above all depressive disorders, and to introduce a therapy. In many cases, however, MCI is an early stage of Alzheimer's disease or other neurodegenerative processes. When such a cause is suspected, the most important medical measure is to monitor the progression of the disease so that when deterioration occurs, therapy with antidementia drugs can promptly begin. In the future, patients with MCI will play an increasingly important role as the target group for the prevention of dementia.