Occupational stress is a global problem imposing harmful effects on the employee's psychological and physical state, and can have a direct impact on the organisation's managers and employees. As a result, it negatively affects their quality of care and productivity. The healthcare sector is one of the significant fields affected by occupational Stress, and it disturbs both hospital performance and patient satisfaction. The study investigates the relationship between occupational stress and critical care nurses' job performance, measures occupational stress levels, and determines the most stressful factors that arise from critical care nurses' occupational stress. This study is a descriptive correlational cross-sectional study conducted at Al-Noor Specialist Hospital, Saudi Arabia, Makkah. An electronic self-administrative survey was randomly distributed to all nurses in I.C.U., CCU, OR, E.R., and the burns unit. It designed to assess nurses occupational stress stressors in the critical care departments. The survey instrument consists of three segments: assessing occupational stress and Nursing Performance. The findings indicates a significant relationship between occupational stress and educational and marital status, offering a higher stress level among single nurses with a master's degree certificate. While, the nurses' performance shows a significant relationship with nurses rank, showing the highest performance among assistant nurses. Furthermore, the study found a significant association between O.S. and the critical care nurses' job performance (P =0.043), and that relationship was a negatively negligible correlation since (r = - 0.191). Performing Further research is necessary, since this study was affected by the COVID-19 Pandemic.

Keywords: Critical Care Unit, Cross-sectional Correlation, Nurses, Occupational Stress, Performance, Saudi Arabia, Work-related Stress.