Background: Leadership style is viewed as a combination of different characteristics, traits and behaviors that used by nurse managers for direct interacting with their staff nurses. Therefore nurse managers have the ability to influence nurses autonomy and their ability to make decisions that positively influences health outcome that lead to organizational success Aim of the study: assessment the effect of leadership styles training program on nurses autonomous decision making. Design: A quasi-experimental research design was used in carrying out this study. Setting: this study was carried out in critical departments at Ain Shams University. Subject: the study subject include two groups as (46) nurse managers and (94) staff nurses. Data collection tool: included four tools will be used to collect data for this study as leadership styles knowledge questionnaire, leadership styles attitude questionnaire, leadership styles skills checklist and autonomous decision making scale. Result: displays, more than quarter (28%) of the head nurses had satisfactory knowledge of the leadership at the pre-intervention phase. This increased to 69% at the post-intervention phase and 83% at follow up. In addition, more than one third of the head nurses had paternalistic leadership style at the pre-intervention and post- intervention phase. While, more than two fifths of the head nurses had democratic leadership style at follow up phase. Also more than half of the head nurses had high level of  leadership skills at the pre-intervention, this improve to most of them at post intervention phase and less than three quarters of them at follow up phase. Conclusion: there was highly statistically significant strong positive correlation between head nurses scores of knowledge and skills. There was highly statistically significant weak positive correlation between attitude of head nurse regarding leadership styles and autonomous decision-making of staff nurses. Recommendations: nurse managers should foster nurses' autonomy by enabling them to exercise clinical decision making and activity supporting nursing decisions and nursing accountability.

Abstract
Background: Leadership style is viewed as a combination of different characteristics, traits and behaviors that used by nurse managers for direct interacting with their staff nurses. Aim of the study: assessment the effect of leadership styles training program on nurses autonomous decision making. Design: A quasi-experimental research design was used in carrying out this study. Setting: this study was carried out in critical departments at Ain Shams University. Subject: the study subject include two groups as (46) nurse managers and (94) staff nurses. Data collection tool: included four tools will be used to collect data for this study as leadership styles knowledge questionnaire, leadership styles attitude questionnaire, leadership styles skills checklist and autonomous decision making scale. Result: displays, more than quarter (28%) of the head nurses had satisfactory knowledge of the leadership at the pre-intervention phase. This increased to 69% at the post-intervention phase and 83% at follow up. In addition, more than one third of the head nurses had paternalistic leadership style at the pre-intervention and post- intervention phase. Conclusion: there was highly statistically significant strong positive correlation between head nurses scores of knowledge and skills. There was highly statistically significant weak positive correlation between attitude of head nurse regarding leadership styles and autonomous decision-making of staff nurses. Recommendations: nurse managers should foster nurses' autonomy by enabling them to exercise clinical decision making and activity supporting nursing decisions and nursing accountability.