Word segmentation is one of the initial processes that needs to be solved when acquiring the first or learning a second language. Acoustic cues like the fundamental frequency and segment durations have been shown to facilitate the detection of word boundaries. The role of visual speech and in particular of lip movements in word segmentation is still rather unknown. In French, liaisons, e.g. between determiner and noun, often pose a problem of several segmentation possibilities (e.g., the sequence /lafiS/ with liaison ("l’affiche") means the poster whereas without liaison ("la fiche") it means the file.). Here, we use 17 ambiguous French sequences with and without liaison. They were presented in carrier sentences either with clear acoustic cues for the first or the second segmentation possibility or with ambiguous acoustic cues. The three audio conditions were combined with lip movements hyper-articulating either the first or the second segmentation possibility in order to observe the influence of visual information on segmentation. Theparticipants had to indicate as quickly as possible which of the two versions they understood (e.g., "l’affiche" or "la fiche"?). Results show that lip information indeed biases the word segmentation decision. These data provide important implications for audiovisual integration processes.