Against the backdrop of the warnings by some previous studies about the danger of the Yorùbá language losing domains because of the increasing dominance of English, the present study examines the broadcast languages of selected radio stations in Osun State, Nigeria, to ascertain the extent of the threat of English to Yorùbá in broadcast media domain. The investigation is carried out within the wider context of the worries being expressed by many speakers of Yorùbá about the status of the language with respect to language endangerment. It employs both quantitative and qualitative research designs rooted in content analysis, and examines 426 purposively sampled programmes of Rave FM and Gold FM. The programmes were sorted and content-analysed using charts. Of the 12 examined programme categories, English is the dominant language of 9 most important programmes, while Yorùbá is the dominant language of 3 programmes; thereby pointing to a gradual loss of the radio broadcast domain. The study recommends more value-added usage of the Yorùbá language in media domains to improve the language's vitality and inclusive audience participation.