The present study seeks to contribute to the ongoing debate about the integration of foreign languages as media of instruction in secondary schools, through exploring Moroccan physics teachers' attitudes towards the use of English and French as media of instruction in secondary schools. Grounded theory methodology, in which data is analysed to generate new hypotheses, is suitable for such studies which seek to describe the reality of bilingual education as perceived by practising teachers. The fifteen physics teachers interviewed in this study show a level of satisfaction in teaching their subjects through a foreign language, French. They think the bilingual program, implemented in Moroccan schools, is a good opportunity for both students and STEM teachers to improve their language proficiency. However, they seem to critique the Ministry of Education for not involving them in the conception of this new language reform. With respect to English-medium instruction, the participating teachers do not think Moroccan schools are ready for the use of English as a medium of instruction. They suggest upgrading the status of English as a foreign language in all levels of schooling and improving both teachers' and students' English proficiency before moving in such a new direction.