The current study is motivated by the dearth of research regarding trilingualism and its relationship with foreign language anxiety (FLA) especially in a bilingual and diglossic context. The present study reports on the FLA level in an underexplored context of seventy-three male and female Arabic-and French-speaking university trilingual students learning English as a foreign language (EFL) in Tunisia. It also examines the main sources of the participants’ anxiety. Using data from the Foreign Language Classroom Anxiety Scale (FLCAS) (Horwitz, Horwitz, & Cope, 1986), analyses revealed that the English learners experienced low to average amounts of FLA. Worry about failing English class, apprehension about speaking in English, and anxiety related to the classroom were identified as major sources of FLA. No association was found between gender and FLA. This study found a significant negative relationship between students’ level of FLA and their exam scores. Implications for language teaching are offered.