Medulloblastoma is a common paediatric brain tumor. Its prognosis is improved since the use of radiotherapy after surgery. This radiotherapy, so widely and complex, has one purpose: tumor control with less toxicity. Frontal relapse of medulloblastoma is not rare. Two hypothesis were proposed to explain this failure pattern: a geographic miss in cribriform plate due to targeting deviation and the migration of tumor cells to the cribriform plate caused by the "face down position" of the patient during surgery. We report the case of a 10-year-old boy who was treated in 1998 for a medulloblastoma with surgery and radiotherapy of the craniospinal axis (24 Gy) and the posterior fossa (54 Gy). Four years later, tumor relapsed only in the frontal area. A new surgery and chemotherapy were used with a complete response. A second frontal relapse associated with posterior fossa recurrence was detected after one year of the second treatment and treated by chemotherapy. Frontal relapse in medulloblastoma is an avoidable failure pattern when surgical and radiotherapeutic procedures are well controlled.