Though we knew it would be difficult to predict whether a child having von Recklinghausen's disease would develop a central nervous system lesion in the future, we tried to find a clue to this question in our study, by comparing computed tomography (CT) findings of 18 children with those of 21 adults. 55% of the children and 85% of the adults showed abnormal findings on CT. The most common finding was mild ventricular dilatation without periventricular hypodensity. Some of them showed ventricular stasis without block on radioisotope cisternography.