Hydranencephaly, first described by Cruveilhier, may be defined as a rare condition in which the cerebral hemispheres are replaced by membranous sacs filled with cerebrospinal fluid. Cerebral angiography is especially useful in differentiating hydranencephaly and severe hydrocephalus, massive subdural hygromas and alobar holoprosencephaly, but it is no better than other neuroradiological diagnosis methods in the neonate. This report outlines the diagnostic use of two-dimensional Doppler (color Doppler) in a child with hydranencephaly. Color Doppler was performed using an SSA-270A (Toshiba) with a 3.75 MHz phase-array sector scanning probe and no sedation. In this study, color Doppler demonstrated the internal carotid artery in the proximal portion, but the secondary and tertiary branches were not observed. In summary, color Doppler permitted early, easy diagnosis of hydranencephaly. In addition, the use of color Doppler was beneficial in diagnosing other anomalies of the central nervous system in neonates.