We estimated the population rates of obstetric haemorrhage and transfusion among women giving birth, utilising data collected in a review of the delivery admissions of 1200 randomly selected women in New South Wales in 2002. The estimated population obstetric haemorrhage rate was 13.1% (11.4% post‐partum haemorrhage (PPH), 2.2% antepartum haemorrhage) and the transfusion rate was 1.06% (0.9% vaginal births, 1.6% of caesarean sections). When variations in definitions and denominators were accounted for, the difference in PPH rates among vaginal births (13.1%) and caesarean sections (6.3%) disappeared, suggesting PPH is under‐ascertained for women delivered by caesarean section.