Dryness of the mouth (xerostomia) is a serious problem for the affected patients, in particular if it is caused by a reduced salivation. Triggering factors are, e.g., drugs (antihypertensives, neuroleptics), CNS disorders, chronic obstruction of nasal breathing, irradiation therapy of head-neck tumors, Sjögren's syndrome, sarcoidosis, or diabetes mellitus. Patients with xerostomia should be diagnosed and treated on an interdisciplinary basis. Several causal and symptomatic therapeutic options are available, including local stimulation of salivation. In addition, prevention is to be emphasized. In most patients symptomatic improvement and thus an improved quality of life can be achieved.