Background: It is necessary to recognize, manage, and avoid incivility in the health care environment, particularly the operative nursing workplace, to create healthy workplaces. Aim Assess the effect of assertiveness training program on improving civility among nurses in the operating room. Design: a quasi-experimental one group preposttest has been used. Subjects: Convenience sample include all nurses. Setting: at Operating room at Fayoum University surgical hospital. Method: The current study data were collected by using four tools; Interview questionnaire which prepared by researcher includes demographic characteristics of the nurses, an assertiveness behavior scale, AES Civility Scale and Perceived Workplace Civility Climate. Results: Main result of this study reveals that there was a positive statistically significant correlation between civility and assertiveness behavior at r= 0.602 and p- value<0.01post assertiveness training program. Also, a significant positive linear correlation between workplace civility climate and assertiveness behavior observed at r= 0.587and p- value<0.01post-intervention. Additionally, a significant positive linear correlation between workplace civility climate and civility detected at r= 0.720 and p-value<0.01 post-intervention. Conclusion: Workplace civility climate in the operating room has been significantly improved post assertiveness training program implementation. Recommendations: In healthcare settings, policies, regulations, and practices are critical for addressing uncivil behavior and establishing a civilized environment.