Multilingual pedagogies draw on learners' prior language knowledge and can offer considerable advantages in learning the target language. Yet language instruction, particularly in foreign language learning contexts, does not often capitalise on the multilingual assets of learners. The goal of this study is to understand what determines the implementation of multilingual pedagogies in two institutes of German as Foreign Language, one in the US and one in India. In this comparative case study, ecological perspectives are adopted to examine what factors impede or foster the use of multilingual pedagogies in adult foreign language instruction in both schools. Data collection methods involved open-ended questionnaires, semi-structured interviews with teachers and an analysis of context-specific documents. Findings revealed that there were encouraging, constraining and contingent factors across both schools. While some factors were common to both schools, and there were other context-specific factors that determined the adoption of multilingual teaching. The results of the study also reflect larger issues such as a gap between theory and practice and a lack of teacher collaboration. The paper concludes with some suggestions on how such issues might be addressed.