Holoprosencephaly is a rare intracranial abnormality. The incidence of holoprsencephaly is between 0.56-0.63 of 10,000 live-born infants10. It has classified into three degrees, alobar, semilobar and lobar. In this case report we are introducing a case of Holoprosencephaly, in 13 weeks of pregnancy which was twin. We could identified this abnormality and the reduction was done in the appropriate time. The role of prenatal sonography in recognition of the malformation and prognostic value of these features are discussed.