Post-partum haemorrhage is the most common cause of maternal death in third-world countries. The objective of this study was to evaluate whether routine administration of sublingual misoprostol, 600 g, reduces post-partum haemorrhage. Significantly fewer women in the misoprostol group experienced a loss of > or = 1,000 ml (11% vs. 17%; 0.66 (0.45-0.98)) or > or = 1,500 ml (2% vs. 8%; 0.28 (0.12-0.64)) of blood. We conclude that sublingual misoprostol reduces the frequency of severe post-partum haemorrhage.