Workers on the frontlines of healthcare are encountering "disturbing" levels of unchecked violence and abuse from both patients and coworkers. Although much has been written about aggression from a variety of viewpoints, little systematic information has been gathered about what nurses' 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 and mental health, resulting in alcoholism, and even suicide. So, this study aimed to identify nature and source of workplace violence as perceived by nurses and to explore the impact of workplace violence on 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 workplace violence- behavior and performance checklist that was adopted from (Ferram, 1995). Results showed that the majority of nurses exposed to verbal violence at workplace. Patients constituted the main source of violence in psychiatric unit. However, physicians and patients' 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. Conclusion: Verbal abuse was the most common type of violence among the majority of nurses at workplace and it has negative impact on nurses' behavior and performance. Recommendations: Training program is essential for nurses to prevent violence and aggression in study settings and collaboration with physicians and other disciplines is needed to decrease violence and its negative impact on nurses' behavior and performance.