Background: Occupational stress has consequences on both the individual and the organization which affects staff nurses' performance. Aim: This study was to study the relationship between occupational stress and level of staff nurses performance at Belkas Central Hospital affiliated to Ministry of Health.design: A correlational descriptive research design was followed in this study. Subjects:The subjects of the study compromised 131 staff nurses in Emergency Department, Dialysis Neonatal Unit and Intensive Care Units at Belkas Central Hospital. MethodTwo tools were used for data collection; the first tool: occupational stress questionnaire to assess their occupational stress level, in addition to socio-demographic characteristics of staff nurses. The second tool was observational checklist to assess staff nurses practice. Results: The study revealed that, staff nurses suffering from high level of occupational stress but their performance were satisfactory. Also there were no statistically significant correlation between staff nurses performance and their stress level. Conclusion and Recommendations: Although most of staff nurses had high level of occupational stress, they also had satisfactory score of performance. Thus, the study recommended that occupational stress should be managed through staff nurses participation in decision making, controlling interruptions, organizing work environment and provide staff nurses with training programs to improve their performance and their ability to cope with stress.