Background: Organizational citizenship behavior (OCB) explains 63% of individual performance. OCB is very important especially in private healthcare organizations because the extra behavior is beneficial in bridging gaps and facilitating communication, coordination, loyalty, and maintenance of interpersonal harmony which are the most influential factor in determining healthcare organizational effectiveness (OE). Objective: To determine The effect of implementing training program on organizational citizenship behavior model for nurse managers on organizational effectiveness. Settings: This study was conducted at Mabert El Asafra East Hospital at Alexandria, Egypt. Subjects: The target population for this study included two groups; group (1) included nurse managers who were working in the hospital(N=23), Group (2) included a proportion sample from all nurses(n=91)Tool: In order to collect the necessary data for the study three tools were used: tool one: Nurse manager's knowledge about organizational citizenship behavior questionnaire, tool two: Nurse managers practice of organizational citizenship behavior observational scale, and tool three: Subordinate nurse's perception about organizational effectiveness scale (OES) Results, there is a positive statistically significant difference between the organizational citizenship behavior knowledge , practices level for nurse managers and organizational effectiveness in the three periods; before, immediately after, and after two months of implementing the training program in the study unit. Conclusion: implementing a training program on the OCB model has a significant impact on healthcare organizational effectiveness (OE). Recommendations: nurse managers should adhere all OCB dimension especially in private healthcare organizations to become a role model to nurses and to increase effectiveness and efficiency.