Twin pregnancy is at increased risk for congenital anomalies. Although twins were relatively infrequent, they accaunted for a disproportionately large portion of adverse pregnancy outcome, primarily as a consequence of preterm delivery, gestational diabetes, and pregnancy induced hypertension. In case of twin pregnancy with a single anomalous fetus, the clinicians are faced with difficult decision-making processes regarding the route of delivery, when to deliver, how aggressively to attempt to prevent delivery. Twin pregnancy discordant for a fetal abnormality can be managed expectantly or by selective fetocide of abnormal twin. Recently we experienced two cases of twin pregnancy with a single anornalous fetus. We reported cases with concerned literatures.