This study examines code-switching, broadly defined as the alternation of languages in the same conversation. While recent research suggests that bilinguals may utilize certain phonetic or syntactic features to anticipate an upcoming language switch (e.g. Fricke, Kroll, & Dussias, 2016; Tamargo, Kroff, & Dussias, 2016), studies of prosodic patterns in code-switching have been lacking. A sample of spontaneous multi-word code-switches (MWCS; n = 407) comprised of at least two words in English and Spanish is taken from the New Mexico Spanish-English Bilingual corpus (Torres Cacoullos & Travis, in prep). The data are prosodically transcribed in Intonation Units (see Du Bois et al., 1993), which enables the analysis of the linguistic properties of MWCS at the interface of prosody and syntax. This study utilizes a novel unit for analysis: The prosodic sentence (PS), defined using intonation (Chafe, 1994). The PS is the basis for characterizing intra-sentential MWCS according to prosodic factors: Prosodic position of MWCS, pause expression, transitional continuity, and length measures. Prosodic factors are furthermore assessed according to switch direction. The MWCS (i.e. bilingual PSs; n = 323) are compared with two sets of PSs: (a) Otherwise monolingual PSs containing a noun of other-language origin--Spanish-origin (n = 78) or English-origin (n = 216); and (b) entirely monolingual PSs (n = 584) with a lexical Spanish (n = 231) or English (n = 238) noun, serving as monolingual benchmarks. Overall, clear prosodic-syntactic properties of spontaneous MWCS emerge and findings highlight the unique prosodic-syntactic signature of MWCS as compared to monolingual stretches without MWCS, part of the norms for combining two languages in bilingual communities.