This article discusses the rationale for using language diaries as a method to evaluate language use and language choice in multilingual contexts, as well as the benefits and limitations of this approach vis-à-vis other research methods. This is illustrated using examples from two contexts: Flemish Sign Language/Dutch bilinguals in Flanders and Gaelic/English bilinguals in the Western Isles of Scotland. In both cases, the language diaries were part of a larger mixed-method study which aimed to evaluate language use and language choice in contexts in which the majority language is in almost all instances the unmarked choice. Language diaries provide a new perspective on individual language practices as they allow for an evaluation of contextualised examples of language use and give insight into the factors that drive language and modality choice, and language ideologies. Language diaries give participants ownership over the information shared with the researcher and provide access to a number of different domains. Despite being based on self-reported practices, their situated nature demonstrates how language use can change through personal circumstances. This in turn contributes to a greater understanding of the use of Flemish Sign Language and Gaelic in the wider sociolinguistic contexts in which these languages exist.