BACKGROUND Uterine anomalies are often first suspected after bimanual or ultrasonographic examination. Currently there are no specific recommendations for further evaluation of asymptomatic women with suspected uterine anomalies in pregnancy. METHODS A young primigravida with a history of an ultrasound diagnosis of bicornuate uterus presented with mild abdominal pain. An ultrasound examination showed a viable 18-week fetus with anhydramnios in the left uterine horn. Labor induction with misoprostol culminated in uterine rupture. At laparotomy, a ruptured left noncommunicating rudimentary uterine horn of a unicornuate uterus was noted. CONCLUSIONS Pregnancies within noncommunicating uterine horns significantly increase the risk of potentially catastrophic outcome, therefore, consideration should be given to performing 3-dimensonal ultrasonography and/or magnetic resonance imaging examinations to determine the nature of uterine anomalies. Caution should be exercised if prostaglandins are considered for use in this setting.