Nurse Manager's main job in contemporary health care organization is to increase degree of employee's participation in decision making and goal setting which in return has greater impact on employee motivation, and satisfaction. This study aimed at determining decision making styles used by Nurse Managers at main Assuit university hospital, and the effect of these styles on Technical diploma nurse' satisfaction. Subject of the study: the sample consisted of 96 Technical diploma nurse and 35 Nurse Managers. Setting: Medical and Surgical units at main Assiut University Hospital. Tools of data collection the data collected using structured questionnaire form. Results: the highest percentage of Nurse Managers were used authoritarian decision making style and the lost percentage were used delegative decision making style. Conclusion: Nurse Managers who were using participative decision making style achieving the highest level of employees' satisfaction. Recommendations Give employees opportunities to participate in goals setting and decisions to increase their commitment toward goal achievement. And further studies should be done including different countries to investigate the effect of cultures on Nurse Managers' decision making styles.