Endoscopic third ventriculostomy (ETV) has become the treatment of choice for non-communicating hydrocephalus. Nevertheless, which technique should be considered of choice to identify features correlating with the failure of an endoscopic procedure and which is the optimal postoperative period care standard are still a matter of debate. Traditional neuroimaging techniques have several limitations in assessing the success of the procedure mostly in the early postoperative period. Indeed, a decrease in the ventricular size is often minimal and not visible before 3-4 weeks. MRI, able to detect the presence of a flow void signal through the third ventricle floor, has been reported to have a significantly high incidence of false positives. In our experience, the continuous measuring of intracranial pressure (ICP) by means of a ventricular catheter has been of great help in verifying the correct functioning of the communication between the ventricle and the subarachnoidal spaces during the first postoperative days. Furthermore, ICP monitoring allowed us to safely deal with the intracranial hypertension that may occur shortly after ETV.