Background: Open-book management as an approach of information sharing can lead to a reduction in anomie and illegal Nurses' behavior. Aim: Assess the relationship between open book management, anomie and illegal nurses' behavior as perceived by nursing staff. Design: Cross sectional descriptive correlational design setting: Main Assuit University Hospital, Al-Eman General Hospital, and Health Insurance Hospital. Sample: A convenience sample (854) nursing staff was involved in the study. Study tools: Personal characteristics of nursing staff, Open book Management Questionnaire, Anomie Scale and Illegal Nurses' behavior were used for data collection. Results: There are highly statistical significant relations between the hospital and OBM, anomie levels and illegal nurse's behavior. Conclusion: There was a highly statistical negative correlation between the studied nurses' perception of OBM, Anomie and illegal nurses' behavior. Recommendations: Encourage open book style of management in order to promote efficient teamwork, to avoid anomie and illegal nurses' behavior, different strategies could be used by managers to prevent organizational cynicism among nurses.