Hydranencephaly is an extremely rare anomaly of cerebral structures that occurs in-utero. Cerebral hemispheres are destroyed with transformation into a membranous sac with cerebrospinal fluid and parts of cortex and white matter. The disorder has an incidence of 0.2% in children. Clinical symptoms in neonates are seizures, respiratory failure, flaccidity or decerebrate posturing. Complete absence of the cerebral hemispheres and falx is present. We present a case of a male newborn with hydranencephaly. A possible correlation with in utero exposure to vasoactive drugs will be discussed.