The present study investigates to what extent acoustic cues to word stress facilitate both offline and online word processing in Papuan Malay. Previous production research has shown acoustic evidence for word-stress patterns in this language, counter to earlier predictions. A discussion of the literature on word stress perception and word stress in Papuan Malay is provided and complemented with reports of three word recognition tasks. The first two presented sequences of acoustically manipulated syllable dyads to native listeners in an offline word recognition task. This was done in order to investigate the individual contribution of each of the acoustic cues (F0, duration, intensity, spectral tilt) to the perception of word stress. F0 appeared a relevant cue when stimuli were embedded in a phrase, not in isolation. A follow-up reaction time experiment (online processing) investigated to what extent word recognition was facilitated when either an acoustically weak or an acoustically strong syllable was the cue to identify a word. Reaction times were shorter for strong syllables than for weak syllables. The outcomes suggest that Papuan Malay has a form of perceptually relevant word stress, which is particularly salient for irregular (ultimate) stress rather than for regular (penultimate) stress.