Schizophrenia is a chronic condition characterized by positive symptoms (auditory hallucinations, delusion), negative symptoms (avolition, social withdrawal), and disorganized thoughts/behaviors. Although the pathophysiology is incompletely understood, several neurobiological mechanisms have been proposed. Treatment usually involves antipsychotic medication as well as psychotherapy and supportive services. When evaluating patients in the emergency department, acute safety considerations are paramount. Patients should be assessed for suicide risk, violence risk, inability to care for self, and the risk of being the victim of a crime. Persons with schizophrenia are at an increased risk of substance use and a variety of medical problems.