The involvement of syllables in the perception of spoken English has traditionally been regarded as minimal because of ambiguous syllable boundaries and overriding rhythmic segmentation cues. The present experiments test the perceptual separability of syllables and vowels in spoken English using the migration paradigm. Experiments 1 and 2 show that syllables migrate considerably more than full and reduced vowels, and this effect is not influenced by the lexicality of the stimuli, their stress pattern, or the syllables' position relative to the edge of the stimuli. Experiment 3 confirms the predominance of syllable migration against a pseudosyllable baseline, and provides some evidence that syllable migration depends on whether syllable boundaries are clear or ambiguous. Consistent with this hypothesis, Experiment 4 demonstrates that CVC syllables migrate more in stimuli with a clear CVC-initial structure than in ambisyllabic stimuli. Together, the data suggest that syllables have a greater contribution to the perception of spoken English than previously assumed. (Contains 7 tables, 3 figures and 3 footnotes.)