This article presents the outcomes of a European study on the main training needs which in-service teachers consider they have in order to adapt to a bilingual education model. The investigation has designed, validated, and administered four sets of questionnaires to 706 informants (241 of whom have been in-service teachers) across Europe, which have allowed a detailed diagnosis of teachers' training needs in terms of linguistic and intercultural competence, theoretical and methodological aspects based on the new options associated with Content and Language Integrated Learning (CLIL), teaching materials and resources, and ongoing professional development. After framing the topic against the backdrop of prior investigations, the article expounds on the research design of the study and outlines its main findings in relation to the aforementioned fields of interest. A detailed diagnosis of where we currently stand in this process of preparation for CLIL models in Europe is provided.