There is no consensus on the nature, or even the existence, of Vietnamese word stress. While some authors have proposed that it is morphosyntactically conditioned (Thompson 1963, Thompson 1965, Cao 2003 , Ngô 1984), others have adopted the view that it is consistently word-final (Trần 1967; Nguyễn & Ingram 2006, 2007b; Phạm 2008; Nguyễn 2010) or that it lacks stress altogether (Emeneau 1951). This is due to the elusive nature of word prominence in Vietnamese, and to the small number of studies that tackle the issue experimentally. In this paper, acoustic experiments designed to test previous hypotheses and tease apart possible types of prominence are presented. Southern Vietnamese disyllabic words with various morphosyntactic structures were recorded in controlled environments to test for stress and phrasal effects. Their duration, mean intensity, mean f0, f0 range and formants were then measured to assess word prominence. Results suggest that there is little evidence for word stress in Southern Vietnamese and that reports of final stress can be reinterpreted as phrase-final lengthening. Focus-marking strategies bring no additional evidence for the existence of stress, but they seem to be partly speaker- and tone-specific, which supports results obtained in studies of Northern Vietnamese (Michaud 2005).