Choroid plexus papillomas of the lateral ventricles are usually benign lesions which occur most commonly in children. These lesions can be accurately diagnosed with adequate pneumographic technique. Movement of the intraventricular tumor and demonstration of the pedicle are specific signs of choroid plexus papillomas. Cerebral angiography demonstrates the lesion and depicts its specific blood supply from the choroidal arteries—a diagnostic feature of these lesions and useful information for their surgical removal. Isotope brain scanning has also proved to be an important and simple procedure in demonstrating choroid plexus papillomas of the lateral ventricles and should be used more frequently in the evaluation of hydrocephalic children.