This paper reports on pilot work on the expression of Information Structure in Vietnamese and argues that Focus in Vietnamese is exclusively expressed prosodically: there are no specific focus markers, and the language uses phonology to express intonational emphasis in similar ways to languages like English or German. The exploratory data indicates that (i) focus is prosodically expressed while word order remains constant, (ii) listeners show good recoverability of the intended focus structure, and (iii) that there is a trading relationship between several phonetic parameters (duration, f0, amplitude) involved to signal prosodic (acoustic) emphasis.