A 22 year-old-man with acute lymphoblastic leukaemia had received prophylactic cranial irradiation and intrathecal chemotherapy. Eighteen years later a cerebellar glioblastoma multiforme was diagnosed. The authors speculate about the possibility that this tumor may have been radiation and/or chemotherapy induced. Improvement in neuroimaging techniques, in particular magnetic resonance imaging, has helped characterize Central Nervous System abnormalities, namely secondary brain tumours.