Background: The leadership is required for building trust and achieving positive organizational outcomes. Organizational commitment acts as one of the outcomes of authentic leadership. Head nurses, as leaders can use an authentic leadership style that positively influence staff nurses and increase their organizational commitment. Aim: The present study aimed to investigate the effect of leadership style on job related tension and organizational commitment among nurses. Methods: A descriptive correlation research design was utilized to achieve the aim of the current study. conducted on all available head nurses (58) working in general departments and intensive care units at South Egypt Cancer Institute at Assuit University. Three tools were utilized for data collection namely; (I) questionnaire consisted of two parts; which included; personal characteristics data sheet, and leader Behavior Description Questionnaire (LBDQ), (II): Job-related Tension (JT) and (III) Organizational Commitment Scale. Results: The highest percentage of study sample were use autocratic leadership style with (75,9%) ,also the majority of the study sample were high role conflict with (93,1%) and high role ambiguity with (94,8 %). Conclusion: The study concluded that there was a negative correlation between leadership styles (delegative and democratic) with conflict and between other leadership styles with affective commitment. However, there was a-positive correlation between leadership style (autocratic) with conflict. Recommendations: The study recommended that leadership educational program should be recognized and implemented for all head nurses who in a management position in the nursing field in other hospitals as needed