There is general consensus as to the importance of fostering plurilingual awareness in educational settings, particularly among students of tertiary education, at both the individual and societal levels, so that they are able to identify the numerous factors that determine a wide diversity of linguistic situations. Thus, this articles focuses on an experience carried out as part of a subject of the Master’s degree in Language Teacher Education at the University of A Coruña, Galicia (Spain). The implications of the plurilingual and pluricultural approach in education are first expounded, with a focus on pre-service teachers in Spanish and Galician educational settings. In the first step of the study, students are asked to write a Language Portfolio, as conceived by the European Union, concentrating mainly on the Language Passport and the Language Biography. In a second phase, students, working in small groups, analyse their Language Portfolios by means of the SWOT matrix, establishing their strengths, weaknesses, opportunities and threats, and determining what they believe they can offer to society as a group of language teachers. Considering the students’ responses, the main topics selected for analysis and discussion are: the place of Galician and Spanish languages in the students’ linguistic repertoires, the proficiency achieved in English, and their learning and use of other languages. The results reveal that these master’s degree students are especially conscious of linguistic diversity, not least because they were born and grew up in a Spanish region where two official languages coexist, but where a situation of diglossia exists. Moreover, as students of foreign languages, they are aware of the significant linguistic consequences arising from phenomena such as globalization.