Medulloblastoma is the most common malignant brain tumour that occurs during childhood. Multimodality treatment regimens have substantially improved survival in this disease; however, the tumour is incurable in about a third of patients with medulloblastoma, and current treatment has a detrimental effect on long-term survivors. Drugs that target cell-signalling pathways provide an alternative to conventional cytotoxic approaches to treatment of cancer. Several pathways have been implicated in medulloblastoma formation, and knowledge of these is now being used to develop new ways of treating children with medulloblastoma.