This paper reports the findings of a study on the attitudes of teachers and students regarding the language policy of the Moroccan educational system. Its primary goal is to explain the gap existing between the policy of Arabisation (i.e., the official adoption and utilization of Standard Arabic) and its practical implementation in science classrooms. Conducted in seven public and private high schools in two major cities in Morocco, the study examines the attitudes of students and teachers towards their level of competence in Standard Arabic, the validity of Standard Arabic as a medium of science instruction, and the future status of Arabisation in science disciplines, in particular, and in education, in general. This attitudinal study can be used to describe the status of Arabisation in the Moroccan education system and to elucidate some of the obstacles impeding its implementation.