The traditional treatment for communicating hydrocephalus is a ventriculo-peritoneal shunt insertion and the endoscopic third ventriculostomy (ETV) is reserved for patients with obstructive hydrocephalus. However, in the last decade several reports highlighted an success of an ETV in communicating hydrocephalus as well. Thus, the aim of the present study is to compare ventriculo-peritoneal shunting against ETV in patients with an idiopathic normal pressure hydrocephalus, an subset of communicating hydrocephalus, in a randomized, controlled multicenter study.