Background. Although there are some cases of cerebellar mutism, in adults after posterior fossa surgery for cerebellar tumour it generally occurs in children. Reversible pathophsiology and the anatomical substrate of this syndrome still remain unclear. The predominance of cerebellar mutism in children is suggested to be related to the higher incidence of posterior fossa tumours in children. However, the question regarding the reason for the obvious difference in the incidence of this syndrome between the paediatric and adult population still remaing unanswered. The aim of this study was to evaluate and compare children and adult groups separately to understand the incidence and the clinical characteristics better and to elucidate the pathophysiological basis and predictive factors for this syndrome.