This study tests how prosodic boundary strength (i.e., categorical differences between Accentual Phrase, AP, and intermediate phrase, ip, boundaries) per se affects the syntactic parsing of spoken utterances in French. Two forced-choice perception experiments demonstrated that French listeners use prosodic boundary strength (either AP or ip boundaries) at the end of noun phrases (e.g., La nana du sauna ‘The girl who manages the sauna’) to choose whether NPs are likely to be followed by a prepositional phrase (e.g., d’Héléna ‘of Héléna’) or instead by a verb phrase (e.g., déconseille ‘advises against’). Experiment 1 employed fragments extracted from natural speech stimuli, while Experiment 2 made use of resynthesized speech, in which fundamental frequency and durational cues to AP and ip boundaries were independently manipulated. In Experiment 1, results show that listeners prefer PP completions following AP boundaries and VP completions after ip boundaries. Experiment 2 shows that preboundary duration cues consistent with the presence of an AP boundary successfully guide listeners to prefer PP completions, while both fundamental frequency and duration cues consistent with an ip boundary are necessary to induce VP completions. We hence argue that prosodic boundary strength at the right edge of an utterance fragment influences syntactic parsing decisions in French.