The aim of this study was to present the outcome of bichorionic twin pregnancies complicated by early second trimester rupture of membranes in one sac. Data regarding all cases of ruptured membranes at 13-20 weeks in bichorionic twin pregnancies were collected retrospectively from three fetal medicine units. Patients who have chosen to terminate the pregnancy were excluded from the study. Between January 2003 and July 2009, nine patients met inclusion criteria. Three out of nine couples decided on expectant management, and six preferred selective feticide. With expectant management one fetus died in utero and take home baby rate was 83% (5 of 6 fetuses), delivered at 27-32 weeks. When selective termination was performed, all non-reduced fetuses were born alive at 33-40 weeks. Two survivors of rupture of membranes had limb contractures, none had lung hypoplasia. One patient had clinical signs of amnionitis, which was ruled out later on pathological examination. Her post partum course was uncomplicated. Our data suggest that rupture of membranes in one sac of bichorionic twins at 13-20 weeks has favorable prognosis whether an intervention is preformed or not. Nonetheless, selective termination may have an advantage over expectant management, since gestational age at delivery was higher when selective termination was performed.