This study aims at testing the effectiveness of additional CLIL (Content and Language Integrated Learning) exposure on the oral production of secondary school learners of English as a Foreign Language. CLIL learners, who had received a 30% increase in exposure by means of using English as a vehicular language, were compared to mainstream English students in a story-telling task. Analyses indicated that CLIL learners’ productions were holistically perceived to exhibit better fluency, lexis and grammar while no differences were found as regards content and pronunciation. Besides, although Non-CLIL learners’ productions were larger in quantity and longer in time, CLIL learners produced denser and more fluent narrations, as attested by their higher number of different words over total number of words, of words over turn, and of utterances over turn. Additionally, CLIL learners resorted to their first language to a lesser extent
and demanded fewer vocabulary clarifications. Our findings thus go along with previous research which has revealed advantages of additional CLIL exposure on oral English production.