To what extent are processes used in sentence production integrated between the different languages of a bilingual and to what extent are they kept separate? We consider three models that differ in their assumptions about the degree of integration: De Bot's [De Bot, K. (1992). A bilingual production model: Levelt's Speaking model adapted. Applied Linguistics, 13, 1-24] bilingual blueprint of the speaker, Ullman's [Ullman, M. T. (2001). The neural basis of lexicon and grammar in first and second language: The declarative/procedural model. Bilingualism: Language and Cognition, 4, 105-122] declarative/procedural model of bilingualism, and Hartsuiker et al.'s [Hartsuiker, R. J., Pickering, M. J., & Veltkamp, E. (2004). Is syntax separate or shared between languages? Cross-linguistic syntactic priming in Spanish/English bilinguals. Psychological Science, 15, 409-414] integrated model. A review of the evidence from bilingual sentence production studies shows that Hartsuiker et al.'s predictions are supported, but argues against the other two models. We discuss some repercussions for bilingual language use.