The most frequent type of cerebellar astrocytoma in children is the pilocytic variety, for which the treatment of choice and prognosis are now well established. In contrast, an anaplastic lesion in this site is extremely rare. The authors present four cases of high-grade astrocytoma in a cerebellar site. They discuss the best type of treatment for this pathology, with particular reference to postoperative radiotherapy and chemotherapy, in the light of their results.