Postpartum haemorrhage is one of the most dreaded obstetric complications and one of the three main causes of maternal mortality in the world. It is universally defined as haematic loss above 500 ml following a vaginal delivery or above 1,000 ml following a caesarean. An early postpartum haemorrhage (EPH) is one that occurs during the first 24 hours following delivery and is generally the most serious. The causes of EPH include uterine atony, trauma/lacerations, retention of products of conception and alterations of coagulation, with atony being the most frequent. Diagnose is clinical and treatment must include general life support measures and other more specific measures of an etiological character. Fortunately, in the majority of cases it is potentially avoidable if an adequate strategy of active and systematic prevention is followed in the delivery phase of all labors.