The focus of this article is on the potential transfer or generalization of positive effects from a treated to an untreated language in bilingual or multilingual individuals with primary acquired aphasia. Twelve studies are reviewed: All were previously published in English in peer-reviewed journals. Half of these studies failed to account for spontaneous recovery. Results from the remaining case reports and single-subject studies are mixed, with four finding evidence for cross-language generalization under some conditions and two finding that improved language performance was restricted to the treated language. Collective findings are discussed within the broader literature in terms of factors to consider when planning for effective, efficient intervention with bilinguals with aphasia.