to acquire clinical skills and decision-making through various situational experiences. Aim: The research aimed to investigate the effect of simulation-based educational program on maternity nurses' performance regarding obstetrical emergencies during pregnancy. Methods: A quasi-experimental research (one group pre/post-test) design was adopted to fulfill the research aim. This research was conducted at the Clinical Obstetrics' Skill lab of the Faculty of Nursing, Benha University. Forty nurses were recruited (all nurses working at obstetrics and gynecology emergency department of Benha University Hospital at the time of collecting data). Three tools were used for data collection; a structured self-administered questionnaire, maternity nurses' attitude assessment scale, and maternity nurses' practices observational checklist. Results: showed a highly statistically significant improvement concerning maternity nurses' knowledge, attitude, and practices regarding obstetrical emergencies during pregnancy, immediate post-intervention, and at follow up phase compared to the pre-intervention phase (P ≤ 0.001). There was a positive, highly statistically significant correlation between total knowledge and total attitude and total practice scores at pre-intervention, immediate post-intervention, and at follow up phases (P ≤ 0.001). Conclusion: The simulation-based educational program positively affected maternity nurses' performance regarding obstetrical emergencies during pregnancy. Simulation-based education regarding obstetrical emergencies during pregnancy is recommended for all nurses working at obstetrics and gynecology units.