Intraamniotic instillation of prostaglandin F2 alpha (PGF2 alpha) is considered by many to be safer than instillation of hypertonic saline for second-trimester abortion. To evaluate the validity of this hypothesis, we reviewed 15 comparisons of these two abortifacients published in the English literature since 1973. These reports suggest that while PGF2 alpha induces abortion faster than saline, PGF2 alpha is associated with higher rates of unpleasant gastrointestinal side effects, incomplete abortion, hemorrhage and surgical reevacuation. In addition, the rate of live-born fetuses after PGF2 alpha-induced abortion may be 5 to 40 times that of saline. The existing literature does not substantiate the claim that PGF2 alpha is superior to saline as an abortifacient.