A retrospective chart review of all anaesthesia consultations for retained placenta at 28 weeks' gestational age or more was performed to determine the safety and efficacy of intravenous glyceryl trinitrate therapy in the management of retained placenta. Of the 33 patients who received glyceryl trinitrate, 1 received a total dose of 50 micrograms and the remainder received 100 to 200 micrograms. All placentas were extracted within 4 minutes of the first bolus. The systolic and diastolic blood pressures and the haematocrit fell by a mean of 8.1 +/- 5.3 mmHg, 6.0 +/- 3.5 mmHg, and 2.6 +/- 1.7%, respectively (mean difference +/- SD, p < 0.05 for each). The pulse rose by a mean of 7.7 +/- 4.5 bpm (p < 0.001). Only 1 patient required ergometrine for continued atony. None of the patients required transfusions or operative therapy other than dilatation and curettage. The use of glyceryl trinitrate in doses of 200 micrograms or less for retained placenta appears efficacious and safe, and may obviate the need for general anaesthesia for uterine relaxation.