The safety, predictability, and ease of intravenous administration of nitroglycerin (NTG) have been firmly documented. In recent years, intravenous NTG has come to the attention of the obstetrician as a potent uterine relaxant. Intravenous nitroglycerin has been used to relax the uterus during manual extraction of retained placenta and to permit replacement of a contracted, completely prolapsed, inverted uterus. The use of this agent as a tocolytic has previously been reported in cesarean delivery of twins, in cases of intra partum external cephalic version, and for internal intrapartum podalic version of the second twin. This new procedure was also used for fetal head entrapment after vaginal breech delivery. The authors report a review of the literature about this subject.