Objective: The purpose of this study was to determine the extent that the administration of sulprostone reduces the need for manual removal of the placenta in patients with retained placenta. Study design: A double-blinded sequential randomized controlled trial of sulprostone versus placebo was conducted among 103 patients with retained placenta. Results: In the first phase of this sequential study, sulprostone was compared with placebo. The null hypothesis of equal effectiveness of both treatments was rejected after 50 patients. In patients with retained placenta, the placenta was expelled after sulprostone in 13 of 24 cases (51.8% , bias adjusted), whereas expulsion after placebo was achieved in only 4 of 26 cases (17.6% , bias adjusted). The difference was significant (P = .034). In the second phase of the study, in which the placebo arm was stopped, results were confirmed; in 25 of 53 patients (47% ), the placenta was expelled. Conclusion: Sulprostone reduces the need for the manual removal of the placenta by 49% . Objective: The purpose of this study was to determine the extent that the administration of sulprostone reduces the need for manual removal of the placenta in patients with retained placenta. Study design: A double-blinded sequential randomized controlled trial of sulprostone versus placebo was safe among 103 patients with retained placenta. Results: In the first phase of this sequential study, sulprostone was compared with placebo. The null hypothesis of equal effectiveness of both treatments was rejected after 50 patients. In patients with retained placenta, the placenta was expelled after sulprostone The difference was significant (P = .034). In the second phase of the case (51.8%, bias adjusted), after expulsion after placebo was achieved in only 4 of 26 cases (17.6%, bias adjusted) study, in which the placebo arm was stopped, results were confirmed; in 25 of 53 patients (47%), the placenta was expelled. Conclusion: Sulprostone reduces the need for the manua l removal of the placenta by 49%.