Background: Primary postpartum hemorrhage PPH is a major cause of maternal morbidity and mortality. Many risk factors for primary PPH have been evaluated, while with changes of obstetric population and technological advances, some of these factors became more important and others were less. Aim: To identify common risk factors of primary PPH and measure the association between these factors and the occurrence of primary PPH. Methods: A case control study was conducted in obstetrics and gynecology department at Zagazig University Hospitals. Participants were selected by systematic random sampling. Data were collected about the participants' age and social class as well as studied risk factors for primary PPH including previous delivery mode, previous antipartum hemorrhage APH, previous PPH, parity, birth weight, gestational age, maternal obesity, maternal hemoglobin level, labor induction, current delivery mode, delivery trauma, episiotomy, placenta previa and retained placenta. Results: Primary PPH was significantly higher among older ages (> 34 years). Primary PPH showed significant associations with the following factors; Previous APH (OR= 3.57), previous PPH (OR= 2.85), macrosomia (OR= 9.57), maternal anemia (OR= 5.37), obesity (OR= 4.01), vaginal delivery (OR= 2.13), labor induction (OR= 2.88), trauma (OR= 3.53), retained placenta (OR= 8.51), and placenta previa (OR= 3.51). Conclusion: Maternal anemia, retained placenta, Macrosomia, and previous PPH were the most significant risk factors for primary PPH. Recommendations: Organized antenatal visits are recommended to help early detection of PPH risk factors and improve females' knowledge about PPH risk. clinicians should optimize care for high risk women. Adequate supplies should be provided to health facilities for prompt management of PPH.