Aim: To investigate the effect of an authentic leadership educational program for first-line nurse managers on nurses' work engagement and organizational citizenship behavior.

Design: A quasi-experimental research design was utilized.

Setting: The study was carried out at Gynecology, Obstetric and Pediatric Minia University Hospital at Minia City – Egypt.

Subject: All first-line nurse managers worked in the inpatient and outpatient units (n = 27), and all nurses who worked in the same units (n = 175) were included in the study.

Tools: four tools were utilized in this research; tool I: authentic leadership knowledge questionnaire, tool II: authentic leadership self-assessment questionnaire, tool III: work engagement scale, and tool IV: organizational citizenship behavior scale

Results: knowledge level and self-assessment about authentic leadership for first-line nurse managers had low score before an educational program implementation; after implementation and after three months of program implementation they had high score with statistically significant differences; also nurses' work engagement and organizational citizenship behavior score increased after implementing authentic leadership education program for first-line nurse managers.

Conclusions: Authentic leadership educational program positively impacted on first-line nurse managers by improving their knowledge and self-assessment about authentic leadership after educational program implementation during various testing times. Also, nurses' work engagement and organizational citizenship behavior score improved after implementing an authentic educational leadership program.

Recommendations: Periodical workshops, training, seminars, and program for the first-line nurse managers to enhance their authentic leadership competencies that increase work engagement and organizational citizenship behavior for their nurses.