Background: Nurses have probably always known that their decisions have important implications for patient outcomes. Nurses are increasingly regarded as key decision makers within the healthcare team. Aim of the study: was to assess centralization and decentralization of decision making in relation to the well-being of nursing staff at their work setting. Research design: a descriptive research design was used to achieve the aim of the present study. Setting: The study was conducted at the Health Insurance Hospital Subjects: Convenience sample included all staff nurses who worked at Health Insurance Hospital with total numbers were 222 nurses. Tools of data collection: Tool (I): centralization and decentralization decision –making scale as well as Tool (II): nurses' well-being at work scale.  Results: The main findings of the study revealed that (78.8%) of the nursing staff have high decentralized decision making and (23.9%) of them have high centralized decision making. Also (7.8%) of them have moderate level of total well-being Conclusion: This study concluded that there were no statistical significance differences between the nursing staff's personal as well as occupational data and (centralized as well as decentralized  decision making. While were no statistical significance differences between nursing staff's personal as well as occupational data and the degree of well-being except attendance a seminar, moreover there was a negative correlation between the nursing staff wellbeing and total centralized as well as decentralized decision making. Recommendations: Increase superior care to staff nurses to ensure that effective and safe care is provided and enhance the work effectiveness as well as nursing staff well being and minimize errors and dissatisfactions