An infant's vocal capacity develops significantly during the first year of life. Research suggests early measures of pre-speech development, such as canonical babbling and volubility, can differentiate typical versus disordered development. This study offers a new contribution by comparing early vocal development in 10 infants with Fragile X syndrome and 14 with typical development. Results suggest infants with Fragile X syndrome produce fewer syllables and have significantly lower canonical babbling ratios compared to infants who are typically developing. Furthermore, the particular measures of babbling were strong predictors of group membership, adding evidence regarding the possible utility of these markers in early identification.