Endoscopic third ventriculocisternostomy (ETV) is a minimally invasive technique that establishes a communication between third ventricle and interpeduncular cistern. We analyzed clinical files of eleven patients (7 males and 4 females) operated on between September 1996 and February 1998. Patients' age ranged from 3 to 61 years. ETV was performed in hydrocephalic patients with neurological signs of increased intracranial pressure (ICP) and CT or MRI diagnosed noncommunicating hydrocephalus (aqueductal stenosis). The fenestration instrument was a monopolar coagulation wire and dilation instrument was a balloon catheter. Post-operative decrease in the third ventricle diameter is the most reliable neuroradiological sign of successful operation. All patients, but one, were able to remain independent of the shunt system after the ETV. ETV is a low-risk neurosurgical technique that should be considered as the initial treatment of noncommunicating hydrocephalus. Features that increase ETV probability of success include age over 1-year, relatively recent obstruction, no meningitis or subarachnoid haemorrhage history and normal ventricular anatomy. ETV excludes mechanical complications and lowers the risk of biological complications which are characteristic for CSF drainage operations. Economic aspect is also very important because drainage devices are very expensive.