Psychiatric disorders per se or treatment resistance can cause life-threatening conditions. More than 25 years have passed since the term “psychiatric intensive care unit” (PICU) was introduced in the United Kingdom. This system is comprised of security units for psychiatric patients with suicidal or violent behaviour, providing a locked environment with more resources regarding personnel and care. The PICU concept at the Department of Psychiatry and Psychotherapy in Vienna, Austria, represents a progress towards optimal care of patients with serious psychiatric illnesses who also have critical somatic illnesses. One third of the patients are transferred from inpatient facilities of medical departments such as internal medicine, emergency medicine, trauma surgery or anesthesiology. Our PICU is dedicated to somatically, critically ill patients who have psychiatric symptoms (e.g., agition, aggression, impulsivity, delusions, catatonia, confusion, reduced consciousness, impaired self-reliance) complicating recovery from their critical, somatic condition. Generally, the dosages for antipsychotics are not higher than those at normal psychiatric wards. Benzodiazepine dosages of about 30mg diazepam equivalents per day are frequently used. In the years 2008 and 2009, 10% of all patients at the Viennese PICU were treated with electroconvulsive therapy. Delirium requires immediate therapy of underlying intracerebral pathologies, extracerebral illnesses or toxic features. Involuntary commitment, physical restraints and urinary catheterization were applied in approximately 50% of the patients, nasogastric tube or central venous catheter in 20%. In every case, intensive care nursing, monitoring of vital functions and specific experience at the interface between psychiatry and somatic medicine are required.