A retrospective examination of all patients referred by the emergency department of a medium sized general hospital for a mandated Form I psychiatric assessment during a 12 month period was conducted. The principal aim was an analysis of the clinical phenomena and especially the antecedents and course of violent behaviour (following admission and throughout the hospital stay) which in the majority of cases was the reason for the referral. Thirty percent had behaved violently prior to admission but within 24 hours all had settled and during the remainder of their hospital stay were indistinguishable from the generality of the ward population (for example, non-violent). Two-thirds of the patients were non-psychotic; that is, not suffering from a major mental illness; nevertheless, they required a disproportionate amount of time and effort in initial management. A high proportion had several prior admissions to the psychiatric ward, particularly for alcohol misuse and/or a personality disorder.