Research on Content and Language Integrated Learning demonstrates that CLIL learners outperform non-CLIL learners with regard to spoken skills and oral proficiency, but that there is a discrepancy between CLIL learners’ receptive and productive skills (Dalton Puffer 2008, Lasagabaster 2008, Lord 2010, Ruiz de Zarobe 2011): CLIL leads to native levels of performance in listening and reading, but to erratic results in speaking and writing. So far, little comparative research has been done on the acquisition of phonology (Dalton Puffer 2008, Ruiz de Zarobe 2011). This paper reports on a series of comparative studies of French-speaking learners of Dutch in CLIL and traditional secundary school education. The variables under consideration are voice assimilation, word stress, pitch accent. The research examines whether there are qualitative and/or quantitative differences between CLIL and non-CLIL learners (compared to native speakers)and to what extent linguistic and/or cognitive factors influence the learners’ phonology. Although the CLIL learners outperform the non-CLIL learners, their phonological skills cannot be regarded as ’near-native’ or ’nativelike’. Also, the performance of the two groups is influenced by linguistic and cognitive factors. During the presentation, we will present the studies’ main findings and discuss their theoretical and educational implications.