The patient expects to receive high quality nursing care, delivered promptly and efficiently by nurses who appear to be satisfied with their workload .This study aims at measuring nurses' workload at trauma and post operative intensive care units. Methods: the subjects consisted of the total number of admitted patients, 112 patients at trauma ICU and 111 patients at post operative ICU and total number of nurses was 68 at trauma ICU and 23 at post operative ICU. Data collected for the period of 3 months by observation of nursing care given to all admitted patients at the selected sites for 24 hours from admission to discharge and Results: Trauma ICU patients and(nursing care given to the patient take about two thirds of 24 hours daily), post operative ICU patients had a workload. Conclusions and Recommendations: As NAS is a new workload measurement system at Assiut University Hospital and almost at Egypt it should be significantly used routinely to identify nurses' workload and to quantify staffing for effective use of nursing resource so: it is important to applying (NAS) to retain staff, and avoid waste of time and Inform staff with patient care results.