Severe neonatal hypernatremia is an important electrolyte disorder that has serious effects on the central nervous system, including brain edema, intracranial hemorrhage, hemorrhagic infarct, and thrombosis. Cerebral venous thrombosis is relatively rare in severe neonatal hypernatremic dehydration. The English literature contains only a few reports of the cranial radiological findings in severe neonatal hypernatremia. The authors report cranial MR venography findings of a newborn infant with severe hypernatremic dehydration. To the best of their knowledge, this is the first such report in the English literature.