This paper begins with a presentation of Levelt and Wheeldon's (1994) model of phonological encoding in language production. Then, the methods used to study this process are presented. In a third part, data on phonological encoding, including speech errors, the tip of the tongue phenomenon, reaction times studies and neuropsychological studies are reviewed. Finally, evidence for the syllable's role as a unit of speech production is presented. A mixed representation of the syllable in which syllables are both chunks and schémas is suggested.