To evaluate the efficacy and safety of misoprostol among patients with retained placenta in a low-resource setting. A prospective, multicenter, randomized, double-blind, placebo-controlled trial was carried out in Tanzania between April 2008 and November 2011. It included patients who delivered at a gestational age of 28 weeks or more and had blood loss of 750 mL or less at 30 minutes after delivery. Sublingual misoprostol (800 μg) was compared with placebo as the primary treatment. Power analysis showed that 117 patients would be required to observe a reduction of 40% in the incidence of manual removal of the placenta (MRP; P=0.05, 80% power), the primary outcome. The secondary outcomes were blood loss and number of blood transfusions. Interim analysis after recruitment of 95 patients showed that incidence of MRP, total blood loss, and incidence of blood transfusions were similar in the misoprostol (MRP, 40%; blood loss, 803 mL; blood transfusion, 15%) and placebo (MRP, 33%, blood loss 787 mL, blood transfusion, 23%) groups. The trial was stopped because continuation would not alter the interim conclusion that misoprostol was ineffective. Treatment with misoprostol was found to have no clinically significant beneficial effect among women with retained placenta. Current Controlled Trials ISRCTN16104753.