Background. Leadership is the life artery of any organization.  A   leader has a significant impact on subordinate's performance, as he creates a positive climate and an authentic support to followers, they work with maximum manner and achieve the best work results. The present study aimed to determine the   relationship of head nurses' leadership styles from staff nurses point of view and staff nurse's performance. A descriptive co-relational research design was used. This study  conducted in Mansoura Emergency Hospital affiliated to Mansoura University. Study subjects consisted of all staff nurses with a total number of 110 working in in-patient units .Two tools were used to collect the data. The first one was the leadership questionnaire geared to measure leadership styles. The second one was nurses' performance evaluation checklist.  Results of the study revealed that transformational leadership style is slightly more than transactional style while both styles do not match adequate level of leader attributes whereas charismatic and intellectual stimulation are obvious items related to transformational style. Level of performance among the staff nurses were relatively low, and all nurses' performance was incompetent and need improvement. There was no statistically significant relationship between leadership styles and nurses performance. So, the study recommended   conducting training programs and workshops to keep head nurses updated at administration and leadership skills, continuous staff nurses development about patient safety, incident report, ethics, nursing process, documentation. Conducting training program about performance appraisal  stressing on feedback for head nurses and their subordinates and finally activating sanction system at hospital are warranted.