Primary post partum haemorrhage is the most common form of major obstetric haemorrhage. The traditional definition of primary post partum haemorrhage is the loss of 500 ml or more of blood from the genital tract within 24 hours of the birth of a baby. Post partum haemorrhage can be minor (500-1000 ml) or major (more than 1000 ml). Major could be divided to moderate (1000-2000 ml) or severe (more than 2000 ml). The recommendations in this article apply to women experiencing primary post partum haemorrhage of 500 ml or more. Secondary post partum haemorrhage is defined as abnormal or excessive bleeding from the birth canal between 24 hours and 12 weeks postnatally. The main causes of the secondary form are: inflammations (endometritis), placental tissue retention, inadequate involution of the uterus and malignancy. Because of its importance as a leading cause of maternal morbidity and mortality, obstetric haemorrhage must be considered as a priority topic. According to the tragic and dramatic outcomes of this morbidity, and to the fact that most cases of post partum haemorrhage have no identifiable risk factors, the practical obstetricians should be aware of the accurate diagnosis and management of this illness.