Workers on the frontlines of healthcare are encountering "disturbing" levels of unchecked violence from both patients and coworkers. Little systematic information has been gathered about what nurse's see as aggression. It was reported that nurses from both academic and clinical settings complained that aggression from colleagues was more problematic to deal with than aggression from patients Negative effects have been observed in terms of lowered performance, deteriorated physical, mental heath and even suicide. This study aims to identify nature and source of workplace violence as perceived by nurses. Also to explore the impact of: workplace violence on the nurses ' behavior and performance. The sample composed of all nurses working at coronary care unit, burn unit, psychiatric unit, emergency unit and a representative sample of nurses working at outpatient clinics of Assuit university Hospital Data were collected by using a structured questionnaire. It included demographic characteristics of the studied sample, items related to the nature and source of violence as well as work place violence behavior and performance checklist that was adopted from (Ferram, 1995). It was that shown that the majority of nurses exposed to verbal violence in different health care settings patients constituted the main source of violence in psychiatric unit. However, physicians and patient's relatives constituted the main source of violence in critical care units and outpatient clinics respectively. Also, it was found that violence has negative impact on nurses' behavior and performance.