The psychiatric emergency is real challenge in medical practice. Thus, Knowing the properties of a population attending an emergency department must improve its functioning.

To estimate the prevalence of psychiatric emergency and to describe its epidemiological and clinical characteristics.

It's a descriptive cross-sectional study of 12 months conducted in the medical emergency department of the university hospital of Mahdia. We have included patients for which a psychiatric evaluation was requested. The Canadian Triage and Acuity Scale (CTAS) was used to specify the degree of the emergency.

The prevalence of psychiatric emergency was 7,9%. The general characteristics were: an average age of 34,7 years old, a sexe ratio (M/F) of 1,38, a single status (66,4%), a secondary education level (45%) and presence of psychiatric personal history (70%). The two most common reasons for consulting were suicide attempts and heteroagressivity in 17,5 and 17,2% of cases. According to the CTAS, the level of emergency was 2, 3 and 4 in 80,9%. 40% of patients were referred to consultation while 39,5% of them were hospitalized in psychiatric departments. For those one, the diagnosis was schizophrenia in 55.7% of cases. The average period of hospitalization was 25 days.

The response to psychiatric emergencies depends on the type of the disorders and the diachronic aspect.