Background: Violent behavior of psychiatric patients is a public health problem. It presents obvious risks of injuries or death of assailants and their victims. Aim: this study aimed to evaluate the effect of the psycho-educational program about violence on nurses' knowledge and practice. Design: A quasi- experimental research design was utilized in this study. Setting: The study was conducted at Tanta Psychiatric and Mental Health Hospital affiliated to ministry of health and population. Tanta city, Algharbya Governorate, Egypt. Subject: A sample of 50 randomly selected psychiatric nurses were recruited for this study. Tools: Two tools were used to collect data; tool I part1: socio-demographic characteristics for nurses, part2: Structured Nurse's Knowledge Questionnaire. Tool II: Observational Checklist for Nurses' Practice Related to Patient Violence. Results: The main result of this study revealed, highly significant improvement in nurses' level of knowledge and practices toward violent patient after implementation of psycho-educational program. Also, there were statistically significant positive correlation between nurses' level of knowledge and level of practice related to psychiatric patients' violence immediately after and 3 months after implementation of the educational program where (r =0.861, P=0.019) (r =0.418, P= 0.003) respectively. But, there were no statistically correlation between nurses' level of knowledge and practice related to violence before implementing the program as r = 0.180, P= 0.211. Conclusion: The present study concluded that, the educational program sessions played an important role in improvements of nurses' level of knowledge and practices toward violent patient. Recommendations: This study recommended implementing further educational program for nurses concerning the pattern of communication and behavioral management for violent patients is very important.