Background and objective: Individuals, who work in an organization where there is a high level of trust, perceive themselves as an important and valued part of this organization. With more enthusiasm, they come to work and are happier with their jobs. Thus, staff nurses' organizational trust, which forms the basis of intra-organizational relationships, can affect their performance and help them to demonstrate organizational citizenship behaviors. The aim of this study was to assess organizational trust and organizational citizenship behaviors from staff nurses' perspective. Also, to investigate the relationship between organizational trust and organizational citizenship behaviors at Alexandria Main University Hospital. Methods: A descriptive correlational design was utilized with convenient sample of staff nurses (n = 352) including staff nurses who works in units of medical care (n = 90), in units of surgical care (n = 120), and in critical care units (n = 142). Two tools were used to measure the study variables: Tool I: Organizational Trust Inventory (OTI). Tool II: Organizational Citizenship Behavior Scale (OCBS). Results: The highest mean score of organizational trust was related to trust in managers, while, the lowest mean score was related to trust in organization. The highest mean score of organizational citizenship behaviors was related to conscientiousness, while the lowest mean score was related to sportsmanship. Conclusions and recommendations: Staff nurses perceived high organizational trust and moderate organizational citizenship behaviors. There is a strong positive high significant correlation between overall organizational trust and overall organizational citizenship behaviors as perceived by staff nurses. Continuous periodic training programs should be given for staff nurses in different healthcare units, to increase their awareness about organizational trust and how to demonstrate organizational citizenship behaviors.