Background: The dynamic nature of the healthcare atmosphere, which involves ambiguity, challenges, and ongoing alterations, has greatly increased the necessity of proactive work behavior. Aim of study: Investigate the relationship between demographic determinants and nurse managers' proactive work behavior. Research question: what is the relationship between demographic determinants and nurse managers' proactive work behavior? Settings: This study was conducted at Mabert El Asafra East Hospital, and Alexandria New Medical Center in Alexandria, Egypt. Subjects: The target population for this study included all nurse managers (N=46) who are working in the previously mentioned setting, and classified as follows; Mobaret El Asafra East Hospital (N=23), and Alexandria New Medical Center (N=23). Tool: To collect the necessary data for the study two tools were used: tool one: Demographic data and work-related characteristics of nurse managers questionnaire, and tool two: proactive work behavior scale. Results, Nurse managers reported moderate levels of proactive work behavior with a mean score of 46.02±5.85. This study implies there were no statistically significant differences between the overall mean score of proactive work behavior and all demographic data and work-related characteristics except for qualification and job position where (p-value = 0.020, 0.010), respectively. Conclusion: the present study revealed that demographic and work-related characteristics have no significant effect on the proactive work behavior level. Recommendations: -Offer nurse managers PWB-focused conferences, workshops, and training courses to increase organizational success.