Aims and objectives: Polysyllabic shortening is thought to contribute to the perception of stress-timed rhythm in some languages. Little is known about its use in the speech of children exposed to a language that incorporates it more frequently (e.g. English) and one that incorporates it less frequently (e.g. Spanish). The purpose of the current investigation was to explore polysyllabic shortening in bilingual children’s two languages compared to monolingual Spanish and English comparison groups. Method/Design: We performed a group-level, cross-sectional study comparing the magnitude of polysyllabic shortening for monolingual English- and Spanish-speaking children and Spanish-English bilingual children. Data/Analysis: Sixteen monolingual English speakers, 23 monolingual Spanish speakers, and 16 Spanish-English bilingual speakers produced two- and four-syllable words in English only, Spanish only, or both English and Spanish, respectively. Ages ranged from 4;5 to 7;7 (M = 5;10, SD = 7 months). English and Spanish words had the same syllable shapes and primary stress locations. Articulation rate was measured by syllables per second. A language history questionnaire and standardized vocabulary test were also administered. Comparisons were made both between and within groups. Results: Both monolingual English and Spanish speakers utilized polysyllabic shortening to similar degrees. Bilingual children produced polysyllabic shortening in English and Spanish to the same degree as their monolingual peers, but they produced it to a greater degree in their own Spanish than in their own English. Conclusion: Polysyllabic shortening might be a universal feature of speech that results from universal phonetic constraints. For the bilingual children, greater use of polysyllabic shortening in Spanish than English may be related to better Spanish than English articulatory control.