The present study focuses on the link between three factors, proficiency, language certificates and bilingualism, and levels of communicative anxiety in the third language (English) in two groups of adult users, university students and young professionals. The first group consisted of 217 university students who were enrolled at the University of the Basque Country (UPV/EHU) and the second group consisted of 135 young professionals working in companies and institutions of the Basque Country. The main aim of this research study is to explore the communicative anxiety towards a third language, English, in a context where exposure to English is limited and there are two other official languages, Basque and Spanish. A variety of instruments were used to collect quantitative and qualitative data. Participants completed a background questionnaire and a questionnaire to measure communicative anxiety. In addition, focus group discussions and interviews were also used. The results indicate that there are significant differences between the two groups of participants (university students and young professionals) in communicative anxiety. The findings also show the relationship between anxiety and some factors such as the proficiency level, English language certificates and multilingualism.