Psychiatric emergency is an acute disturbance of behavior, thought or mood of a patient which if untreated may lead to harm, either to the individual or to others in the environment. Psychiatric emergency is a disturbance in thought, mood and/or action which causes sudden distress to the individual and or disability, thus requiring immediate management. Psychiatric emergencies include suicide, overactivity, aggressive and violent behavior, underactivity, psychiatric disorder with acute onset (acute psychosis), adverse drug reaction, alcohol and drug dependence, other psychiatric emergencies. Crisis is a disturbance caused by a stressful event. Crisis intervention is emergency first aid for mental health and domestic violence. Nurses should have basic knowledge and skill in the management of psychiatric emergencies. Nurses very often have to participate in various community based crisis intervention modalities.