While the role and origin of prosodic structures remain unclear, there is evidence that prosody bears an intriguing relationship with serial memory processes and grouping effects. This link is seen in the fact that the recall of presented prosodic patterns and their production in speech are both restricted in term of a syllable count. The present experiment complements previous studies by examining the effects of syntactic structure as opposed to constituent length on produced tonal groups. Forty subjects produced, in quasi-spontaneous conditions, given utterances with differing NP, VP structures or differing lengths. The results show that constituent length is the major predictor, whereas syntactic structure appears as a secondary factor.