OBJECTIVE: To analyze the outcome of endoscopic third ventriculostomy (ETV) in the management of obstructive hydrocephalus (OHC). METHODOLOGY: This observational study was conducted at department of neurosurgery, Lady Reading hospital, Peshawar Pakistan from January 2009 to June 2012. During the study period, 130 cases of OHC secondary to posterior fossa tumor undergoing ETV were selected for study through convenient sampling method. The exclusion criteria consisted of patient’s age