Emergent cerclage may be defined as that performed in the setting of advanced cervical dilation with bulging or "hourglass" membranes. During a five year period, 15 patients with bulging or hourglass membranes and marked cervical dilation in the second trimester were treated with emergent cerclage. Included were two triplet gestations. Complications were limited to intraoperative rupture of fetal membranes in two patients and chorioamnionitis either in the early postoperative period (two) or later in pregnancy (three). Pregnancy was prolonged for a sufficient time to deliver viable fetuses in 11 of 15 patients. Eleven of 13 neonates of a gestational age of 24 weeks or more survived. The lack of significant maternal morbidity combined with the results for the fetus-infant supports further efforts in this area.