A new PGE2 derivative (16-phenoxy PGE2 methyl sulfonylamide sulprostone) was administered by the i.m. route to 48 women pregnancy in any of the three trimesters. The indications for pregnancy interruption were either serious medical problems in intact pregnancies (21 cases) or due to fetal death in utero (27 cases). Single doses of 500 micrograms were repeated every 4 hours in the former group or every 6 hours in the latter category for a maximum period of 24 hours. The treatment was successful in 81% of intact pregnancies and in 92.6% of fetal death cases with an overall mean induction interval of 12.9 hours. More than half the subjects did not experience any side effects apart from mild or moderate uterine colics. An overall mean of 1.4 episodes of vomiting or diarrhoea per induction trial was quite acceptable from the clinical point of view. The absence of serious complications in the group of critically sick women speaks in favor of the relative safety of the drug.