Background: Staff’s level of empowerment plays a significant role in the success of hospitals as complex systems. Therefore, using effective leadership styles by head-nurses is necessary to create an ideal clinical environment to make the most from nurses’ abilities and potential capabilities.Objectives: The current study aimed to evaluate the relationship of nurses and head-nurses’ psychological empowerment with head-nurses’ leadership style.Methods: This correlational study was conducted on nurses and head-nurses working in Valiasr (PBUH) hospital, Birjand, Iran, recruited through the census method. All participants held bachelor’s degree with a minimum work experience of two years. The data were collected by a demographic questionnaire, the leader behavior description questionnaire and the Spreitzer psychological empowerment questionnaire. The questionnaires were given to the participants in different working shifts. Finally, thirteen head-nurses and 170 nurses completely filled their questionnaires. The SPSS software ver.16.0 was employed to analyze data through conducting the Fisher exact, the Spearman and the Mann-Whitney U test, in addition to the independent-samples T-test, at a significance level of 0.05.Results: All head-nurses were married and above 35 years old and 84.6% of them were female. Moreover, most of the nurses were female (75.9%) and married (82.4%) and aged 26 - 30 years. Most of head-nurses (69.2%) believed that they used the selling leadership style while most of the nurses (76.9%) noted that their head-nurses’ used the telling style. All these nurses and head-nurses had higher levels of empowerment compared with other nurses.Conclusions: The study findings revealed that the nurses who were empowered had perceived their managers’ leadership style to be the telling style. This finding showed that managers’ leadership style was not congruent with staff’s level of empowerment, denoting managers’ poor familiarity with leadership styles. Therefore, educating managers about leadership styles seems crucial to enhance staff’s empowerment, working motivation and efficiency and promoting organizational dynamism.