Remembering the sound of a new word when it is first encountered is an important skill which plays a critical role in the development of vocabulary (Gathercole & Baddeley, 1989), yet the mechanisms underlying this form of verbal short-term memory are not well understood. Errors in the repetition and serial recall of nonwords indicate that structural properties of the syllable are represented in short-term memory, but existing accounts of serial learning and recall do not incorporate any representation of linguistic structure. Models of speech production implicate syllable structure in the representation of phonological form, but do not explain how such representations are acquired. This thesis draws together theories of speech production and serial memory to develop a computational model of nonword repetition based on the novel idea that short-term memory for the serial order of a sequence of speech sounds is constrained by a syllabic template. The results of simulations using the model are presented and compared with experimental findings concerning short-term memory for nonwords. The interaction of short- and long-term phonological memory systems and the aquisition of vocabulary are discussed in terms of the model. The model is evaluated in comparison with other contemporary theories.