In malingering and factitious disorder, the patient pretends to be ill or intentionally causes his or her own symptoms. This chapter reviews the diagnosis, assessment, and management of these, often difficult, patients, providing practical advice to the emergency physician. Malingering and factitious disorder are both forms of somatization in which the patient is aware of producing or feigning their symptoms. A sub-category of factitious disorder, Munchausen syndrome, named after the famous 18th century traveling storyteller, Baron von Munchausen, is characterized by patients who travel widely and tell elaborate tales about their illnesses and treatments thus becoming career medical imposters. Both malingering and factitious disorder are diagnoses of exclusion. While recognition is the first step in the psychiatric management of malingering and factitious disorder, this is not easy to do when an unknown patient presents to the emergency department (ED). The chapter summarizes recommendations for the management of these disorders.