Four cases of cerebellar medulloblastoma with skeletal metastases have been described. Extracranial metastases from this tumour are extremely rare but the skeleton is the site most commonly involved. The metastases did not occur after ventriculo-atrial shunting, but in one of the cases, the diagnosis was made from the check X-ray taken on the day a shunt was introduced. The influence of vincristine sulphate and cyclophosphamide on the radiological appearances and management of the cases has been described. After the diagnosis of skeletal involvement was made three of the children survived over a year with cytotoxic drug treatment; the other case did not respond satisfactory and died from widely disseminated metastases of the central nervous system, 4 months after starting treatment.