Agenesis of the corpus callosum is not an uncommon congenital malformation in neurologically symptomatic children. The computed tomographic scan characteristics of uncomplicated agenesis of the corpus callosum include: (a) widely separated parallel or nonconverging lateral ventricles; (b) "Bat wing" or "bullhorn" appearance of the frontal horns; (c) High-riding third ventricle which may be enlarged and have a tear-drop or rhomboid appearance; and (d) Selective dilatation of the occipital horns occurs frequently. Associated malformations identifiable by computed tomographic scan include Dandy-Walker cysts, interhemispheric cysts, porencephaly, Arnold-Chiari II malformations, and skull deformities.