A variety of complications in endoscopic third ventriculostomy have been reported, including neurovascular injury, hemodynamic alterations, endocrinologic abnormalities, electrolyte imbalances, cerebrospinal fluid leakage, fever and infection. Even though most complications are transient, the overall rate of permanent morbidity is 2.38% and the overall mortality rate is 0.28%. To avoid these serious complications, we should keep in mind potential complications and how to prevent them. Proper decisions with regard to surgical indication, choice of endoscopic entry and trajectory, careful endoscopic procedures with anatomic orientation, bleeding control and tight closure are emphasized for the prevention of complications.