Hydrocephalus is a common problem in pediatric neurological and neurosurgical practices. In this manuscript, the common imaging appearances of hydrocephalus are discussed in relation to the underyling causes of the hydrocephalus. Moreover, specific findings seen on magnetic resonance imaging (MR) examinations are discussed and contrasted with those on computed x-ray tomography (CT) and ultrasound. Finally the imaging findings associated with treatment of hydrocephalus are discussed. In particular, analysis of shunt function, the diagnosis of shunt failure, and the complications of shunting are stressed.