A total of 35 children – 20 with expressive specific language impairment (SLI-E) and 15 typically developing (TD) peers – were compared longitudinally from 24 to 36 months with respect to their production of syllable shapes in 10-minute spontaneous speech samples. SLI-E 24-month-olds predominantly produced earlier developing syllable shapes containing vowels, liquids, and glides. TD 24-month-olds and SLI-E 36-month-olds produced approximately the same proportion of syllable types, with the exception of consonant clusters, where TD 24-month-olds produced more than SLI-E 36-month-olds. TD children at 36 months showed the greatest use of syllable shapes containing two different consonants and consonant clusters. Detailed analyses revealed that SLI-E children produced fewer syllable shapes containing final consonants, more than one consonant type, and consonant clusters. Furthermore, the children with SLI-E were found to vocalize less often than their TD peers. The possible relationships between these findings, SLI-E children's concomitant deficits in morphology and syntax, and the implications for diagnosis and remediation are discussed.