This paper discusses methodologies for examining the multilingual language experiences of young deaf children that are sensitive to different cultural contexts of childhood, caregiving and language practices. We argue that in the context of early support, the combined use of situated multilingual and multimodal approaches to examine and assess individual language resources can provide rich and reliable information about individual communicative repertoires in their given context. This approach extends commonly used monolingual and unimodal research and assessment tools that lack the inclusivity of reach and granularity of analysis needed to inform contextually appropriate early intervention for multilingual and migrant deaf learners. We illustrate the potential of these methods using case study examples from multimodal video-based and ethnographic data gathering and analysis techniques deployed across three projects in different multilingual contexts, in Ghana and the UK. We use these case studies to examine the methodological choices, challenges and opportunities of researching different multilingual environments in culturally sensitive ways as a basis for supporting and assessing the language and communication development of young deaf children in multilingual and migrant contexts. We discuss how the resulting new knowledge base can extend Euro-Western epistemologies that are currently leading models of early intervention and support.