A patient is described who had congenital vascular malformation of the vein of Galen, with several psychiatric, as well as neurologic, manifestations. Prior to this patient's death, there was an increase in some psychiatric manifestations in response to suggestions of surgical therapy for the cerebral venous anomaly. Other symptoms appeared to represent direct organic effects of the lesion. The medical literature on the anomalies of the great vein of Galen reveals a frequent but not specific relationship to concomitant psychiatric manifestations.