We have neuroradiologically and neuropsycho-physiologically studied a case of chronic hydrocephalus due to congenital acqueductal stenosis, before and after ventriculoperitoneal shunting. The aims of the study were: 1) to point out the correlation between neuroimaging (Computerized Tomography/Magnetic Resonance Imaging) and mapping of Computerized Spectral Analysis EEG (CSA-EEG); 2) to monitor evoked bioelectrical activity by neurophysiological evaluation of acoustic and visual N1 and P3. Both bioelectrical activity and neuroimaging evaluation showed a considerable recovery of the neurobiological substratum after neurosurgical shunting, while neuropsychological investigation showed a slight improvement in all cognitive tasks.