BACKGROUND: Uterotonics are essential in reducing the risk of postpartum haemorrhage (PPH) and saving mothers' lives. However, numerous quality-testing studies have found that uterotonics in many low- and middle-income countries are substandard. This study compares the economic, health, and policy implications of poor-quality uterotonics in three West African countries: Ghana, Nigeria, and Senegal. The economic impact of poor-quality uterotonics has not been previously compared. METHODS: We utilized a decision-tree model to examine the implications of using substandard uterotonics (oxytocin and misoprostol) in three countries. The model simulated the place and mode of delivery, use and quality of uterotonics, risk and diagnosis of PPH and resulting economic and health outcomes. Country-specific inputs were derived from demographic and health surveys and published literature. Given large variations in population size, results were compared across 100 000 women giving birth. RESULTS: Ghana demonstrated the greatest benefit from improvements in uterotonic quality, with US $2 million (13%) in annual cost savings and 2200 (11%) cases of PPH avoided per 100 000 women giving birth. Comparatively, annual cost savings were estimated at US $1.1 million (7%) and US $224,000 (7%) per 100 000 birthing women in Nigeria and Senegal, respectively. The yearly reduction in PPH cases per 100 000 birthing women was projected at 875 (6%) for Senegal and 944 (4%) for Nigeria. Taking varying population sizes into account, we saw that improvement in uterotonic quality could annually save US $89 million in Nigeria, US $18.8 million in Ghana and US $1.3 million in Senegal, leading to 100 000 fewer PPH cases per year overall. These simulated results were primarily driven by high proportions of substandard uterotonics and high facility use in Ghana, high numbers of home births in Nigeria and substandard misoprostol use in Senegal. CONCLUSIONS: Improving uterotonic quality would bring significant cost savings and maternal health improvements across countries. Specific policies to improve uterotonic quality and bring about the economic and health benefits may need to be tailored by country. Ensuring the quality of uterotonics is essential in improving medicine equity and would contribute towards efforts to achieve universal health coverage by ensuring that medications adequately achieve their value for money.