This paper reports results of a phonetic study of acoustic exponents of metrical prominence in Mojeño Trinitario, an Arawak language of lowland Bolivia. Mojeño Trinitario displays a rhythmic syncope pattern that deletes vowels in non-final open syllables in metrically weak positions. The acoustic properties of duration, amplitude, and fundamental frequency are consistent with the predominantly iambic metrical parse predicted by rhythmic syncope, although there is interspeaker variation in how these properties are deployed to signal metrical prominence. Phonetic evidence overall supports a tripartite distinction between primary stressed, secondary stressed, and unstressed syllables, where the rightmost metrically strong syllable carries primary word stress.