Educational experts are in a continuous effort for a more effective and efficient EFL model to meet personal communication needs of learners in English starting from an early age. Present outcomes of the EFL programs implemented in Turkey does not seem very promising and a search for more effective foreign language teaching practices has gained importance. As one of the solutions that private educational institutions have implemented is immersion programs, which is based on bilingual classroom practices. In this study it is aimed to investigate the effects of immersion programs on elementary students' native language development through viewpoints of classroom teachers at a bilingual school in Ankara. A focus group was selected randomly among elementary school students, and a semi structured interview was conducted and recoded with 7 classroom teachers. The answers were analyzed via MAXQDA 11 qualitative analysis program. The results show that there is no significant effect of bilingual teaching on students' native language development. (C) 2015 The Authors. Published by Elsevier Ltd.