Background: Postpartum hemorrhage (PPH) is an obstetric emergency. It is one of the leading five etiologies of maternal deaths worldwide, although the absolute risk of death from PPH is much higher in low-resource countries. It accounts for at least 100,000 deaths each year worldwide and contributes up to 28% of maternal deaths. Timely diagnosis and proper management are essential for preventing PPH-related maternal deaths, Aim and objectives: to assess the efficacy of administration of Tranexamic Acid in Prevention of postpartum hemorrhage in high risk women for PPH undergoing cesarean section, Subjects and methods: Our study was conducted at Obstetrics and Gynecology department, in Benha University & Nasr City police Hospitals. A comprehensive sample was taken including all women who are at medium and high risk for PPH after cesarean section birth. Cases were divided into two groups: a study group and a control group. (25 cases in each group), Result: There was high significant difference between the two studied groups according to blood loss (150cc/pack) and blood transfusion after using tranexamic acid, Conclusion: Tranexamic Acid is effective in Prevention of postpartum hemorrhage in high risk women for PPH under- going cesarean section,