The training of language teachers still follows traditional models of teachers' competences and awareness, focusing solely on the target language. Such models are incompatible with multilingual pedagogy, whereby languages are not taught in isolation, and learners' background languages are activated to enhance the process. When teaching bilinguals/multilinguals, the English-only policy is inadequate, and teachers' competence in only one language may not suffice. Thus, an extended model of teachers' plurilingual awareness is proposed, including metalinguistic, psycholinguistic and sociolinguistic awareness, and the traditional model of teachers' language awareness as a part of the cross-linguistic component. In the model, teachers' plurilingual awareness partly stems from their multilingualism.The impact of multilingualism on teachers' awareness was tested on Polish teachers of English (N = 222) differing in language knowledge beyond English (L3-Ln). Their attitudes towards principles of multilingual pedagogy were surveyed. Next, cluster analysis was used to differentiate between the teachers' degrees of proficiency in other languages known, and factor analysis was run to identify the main factors in the survey, which correspond to the components in the teacher's plurilingual awareness model. A subsequent MANOVA revealed that English teachers' multilingualism indeed underlies their plurilingual awareness and readiness to comply with multilingual approaches to teaching.