Background: Postpartum Hemorrhage (PPH) is an obstetric complication that is lead to maternal morbidity and mortality. Training nursing students to prevent and manage PPH is a fundamental principle of risk management. Using high-fidelity simulation at nursing colleges can bridge the gap between theory and practice by using all learning domains. The aim of this study:was to determine the effect of high-fidelity simulation-based training program on nursing students' performance, self-efficacy and confidence regarding prevention of PPH. Subjects and method: the study was conducted in two Settings; (1) Clinical obstetric laboratory skills for academic third year at Faculty of Nursing, Tanta University and (2) Labor unit in obstetric department at Tanta University Hospital. Subjects: A cluster random sample of 60 nursing students in the third academic year who fulfilled the inclusive criteria was included in the study and was divided into two groups; each of them consisted of 30 students. Four tools were used for data collection; Tool (I): A structured interview schedule, comprised of two parts as follows; Part I: Socio-demographic characteristics of nursing students. Part II:Students' knowledge regarding PPH. Tool (II): Students' performance observational checklist contained two parts as following; Part I: Prevention of atonic PPH during the thirdstage of labor and Part II: Prevention and management of PPH of atonic PPH during fourth stage of labor. Tool (III): Self-efficacy Scale. Tool (IV): Modified self-confidence measurement scale. Results: Students' knowledge, performance, self-confidence, as well as self-efficacy regarding prevention and management of PPH were higher after using high fidelity simulation-based training program. Conclusion and recommendations:The use of high fidelity simulation in teaching improved the nursing students' three domains of learning; knowledge, skills, and attitude for prevention and rapid effective nursing response for managing PPH. Therefore, high-fidelity simulation training programs and refreshing courses should be incorporated in the basic nursing educational curriculum as well as for maternity nurses to improve their knowledge, practice, self-efficacy, and confidence