This papers looks at bilingual books for German-speaking learners of English and discusses their potential for vocabulary acquisition. Specifically, it focuses on bilingual books following a sociolinguistic structural principle, i.e. books in which the arrangement of languages reflects multilingual practices of non-monolingual language users. The paper combines corpus analysis and analysis of didactic potential. It reports total words (types and tokens), type-token ratio and distribution across frequency-band classes for three representative bilingual books, and two typical graded readers. It argues that in an assessment of bilingual books' potential for vocabulary acquisition, the relatively low number of target language words has to be balanced against their rich context (especially rich in right-sided context & equivalence cues).