We investigated the interrelation between cognitive and motor development and the role of the cerebellum in this relationship by examining performance in each of these domains in 15 children with injury to the cerebellum following tumour before 5 years of age and 242 typically developing control children aged 4–11 years. Each child was given a comprehensive standardised battery of cognitive and motor tests. Results showed depressed levels of performance for the cerebellar patients across both domains at the group level but considerable variation in individual profiles. However, a significant, positive correlation between cognitive and motor skill was found for both the patient and control group, suggesting these domains are developmentally linked. In addition, the effects of several potential moderating variables were explored. Results showed the most reliable predictors of outcome were age at diagnosis and tumour type/treatment. These results suggest that both cognitive and motor skill can be compromised following tumour in the cerebellum in early childhood leading to delayed, but qualitatively typical, development in both domains.