Endoscopic third ventriculostomy (ETV) has gained acceptance as the treatment of choice for noncommunicating hydrocephalus despite a relatively high failure rate and a higher surgical risk than the placement of a shunt. The benefits of shunt independence overcome both drawbacks. This argument also serves to consider candidates for ETV patients with a poor chance of success, a fact which may to a certain degree explain failure rates higher than 20% in most unselected series of patients with noncommunicating hydrocephalus.