A multicentre study was undertaken to study intramuscular 15(S)15 methyl PGF2α (Prostin 15M, Upjohn) for induction of second trimester abortion. The patients were premedicated with Imodium and Perinorm to control the gastrointestinal side effects. The dose of Prostin 15M was 250 µg every two hours and the progress of the abortion was assessed before each injection. If there was no progress at the end of 10 injections the case was classified as a failure. Ninety‐seven patients were recruited for the study, 39 were primigravidae and 58 multigravidae. Twenty‐four out of 39 primigravidae and 52 out of 58 multigravidae aborted with the treatment. The mean induction abortion interval was 17.8 hours in the primigravidae and 14.5 hours in the multigravidae patients. The mean number of episodes of vomiting was 2.9 and diarrhoea 4.2 per patient per trial. The primigravidae had slightly higher incidence of gastrointestinal side effects. The overall incidence of incomplete abortion was 17.1%.