This paper explores the notion that bilingualism may predispose a posterior aphasic to developing a jargonaphasia. The plausibility of this prediction is based on two assumptions: (1) that jargon reflects a decoupling of phonological representations and representations of meaning; and (2) that bilingualism promotes a decoupling of phonological representations and meaning representations. The paper describes aphasic jargon in its various forms, distinguishing it from paraphasic and stereotypic speech. It then presents a microgenetic explanation of language processing with particular reference to jargon production, and shows how this model applies to language processing in the bilingual. The argument presented is that the conceptual system of the bilingual can be encoded in the features of either one of two linguistic systems, and consequently, the processing routines from conceptual to phonological form are likely to be less automatic for the bilingual. If jargon represents a failure of a given conceptual representation to be realized in a phonological representation, it is more likely to occur in bilinguals, in whom the processing routines have not achieved the same level of automaticity as in monolinguals. It is also suggested that since it is only at the conceptual level that the language systems of the bilingual are unified, the issue of automaticity of processing routines will not distinguish between monolinguals and bilinguals beyond the interface between that level and the lexical semantic level and that there will be no difference between monolinguals and bilinguals with respect to the encoding of lexical representations into phonological forms.