Two word-spotting experiments were conducted to assess the role of syllabe onsets and offsets in lexical segmentation. Participants detected CVC words embedded initially or finally in bisyllabic nonce strings with aligned CVC.CVC or non-aligned CV.CCVC syllabic structure. Misalignment of word and syllable onsets in the spotting of item-final words produced a greater perceptual cost than the misalignment of word and syllabe offsets. These results support the view that the syllabic structure of continuous speech is mainly used to locate potential word onsets. The implications of these findings for the nature of spoken word recognition are discussed.