Background: Developing leadership and management competencies for nursing managers is critical to the effective leadership of others and driving team and organizational performance. This paper aimed to evaluate the impact of a system-wide nursing leadership quality improvement initiative in a network of four public hospitals and one specialized outpatient center in the United Arab Emirates (UAE). The initiative was designed to enhance nursing middle managers’ leadership and managerial competencies. Methods: This is a quantitative evaluation following the Standards for Quality Improvement Reporting Excellence (SQUIRES) guidelines. Secondary Data analysis of a pre- and post-course self-assessment for 105 middle nursing managers who attended a nursing leadership quality improvement training program between December 2017 and April 2019. Results: Following participation in this quality improvement initiative, the paired sample t-test analysis demonstrated a statistically significant difference between the pre- and post-assessments total and individual leadership domains mean scores. Conclusion: Attending well-structured nursing leadership quality improvement programs positively enhances nurse managers’ professional abilities and perception of their management and leadership competencies. Leadership development programs should equip managers with the skills and tools to achieve their professional goals effectively and support their transition to becoming expert nurse leaders. Healthcare institutions’ ethical obligation is to provide them with the necessary resources and training to achieve this goal.