The purpose of this thesis is to investigate the relation of word stress to word segmentation in a cross-linguistic perspective. Word segmentation is the division of continuous speech into words by listeners; a non-trivial task, since spoken language is fast and words are not divided by silences despite listeners' strong intuition to the contrary. This intuition may originate from the fact that language is equipped with many cues to word boundaries, most of them language-specific. Word stress is hypothesized to be one of these cues. The thesis takes a typologically broad cross-linguistic approach to the use of edge-aligned word stress in processing and it is concerned with language-specificity, the direction of processing and the abstract nature of stress as a leading beat on the one hand, and a grouping cue on the other. The thesis concludes with an excursion into first language acquisition, regarding the issue of whether word stress can be inferred from the distribution of stress patterns in continuous speech.