Three hundred ninety-six children with scaphocephalies were prospectively studied to analyze the correlation between age, intracranial pressure (ICP), and mental function outcome. The ICP measurements and the early and late psychometric assessments were compared. The influence of surgery, when performed, was analyzed. In most cases, the mental function outcome of the patients was good whether or not they had undergone surgery. The mental level and the frequency of increased ICP both correlated with patient age. A correlation was found between the early and late psychometric assessments in all patients. Thus, the main predictive factor of mental function outcome appears to be the initial developmental level.