A mild deﬁcit in the cerebellum has been proposed to underlie a wide range of cognitive and behavioural indicators of dyslexia that were formerly explained by the phonological deﬁcit hypothesis and double-deﬁcit models of reading disability, as well as other unexplained symptoms observed in dyslexia (Nicolson, Fawcett, & Dean, 2001). In its earliest form cerebellar deﬁcit theory was introduced within a cognitive framework of automaticity, postulating that dyslexic children have difﬁculties in becoming ﬂuent in any learned skill (Nicolson & Fawcett, 1990). The incorporation of a neurological (cerebellar) basis underlying this apparent automaticity deﬁcit is a more recent development (Nicolson & Fawcett, 1999; Nicolson et al., 2001). However, the speciﬁc role of the cerebellum in dyslexia is not strongly established as there are some inconsistencies in the existing evidence. Moreover, empirical evaluations of an intervention based on the cerebellar deﬁcit theory do not present convincing evidence, largely due to methodological issues. Consequently we argue that this area requires further investigation.