This study calculated the net benefit of using active management of the third stage of labour (AMTSL) rather than expectant management of the third stage of labour (EMTSL) for mothers in Guatemala and Zambia. Probabilities of events were derived from opinions of experts, publicly available data, and published literature. Costs of clinical events were calculated based on national price lists, observation of resources used in AMTSL and EMTSL, and expert estimates of resources used in managing postpartum haemorrhage and its complications, including transfusion. A decision tree was used for modelling expected costs associated with AMTSL or EMTSL. The base case analysis suggested a positive net benefit from AMTSL, with a net cost-saving of US$ 18,000 in Guatemala (with 100 lives saved) and US$ 145,000 in Zambia (with 467 lives saved) for 100,000 births. Facilities have strong economic incentives to adopt AMTSL if uterotonics are available.