The present case study examines Tunisian business speakers’ (TBSs) attitudes towards their code switching behaviour in two business companies. The varieties of languages investigated are Tunisian Arabic, Modern Standard Arabic, French and English. The research seeks to identify the varieties of languages used and the TBSs’ evaluation of the status of each variety used in Tunisian business exchanges. It further examines the linguistic performances of TBSs and the social constraints on their interactions. The findings are primarily derived from an instrument designed to measure the TBSs’ attitudes and are supplemented by information gathered from observations, questionnaires and interviews. The case study revealed significant results concerning the TBSs’ implicit and explicit attitudes towards the varieties of languages used in the businesses investigated. It also presented considerable findings on their code switching behaviour along with their linguistic performances.