In response to globalisation and internationalisation of both higher education and the job market, The Hague University of Applied Sciences (THUAS) has seen a considerable increase in English-medium courses, i.e. non-language subjects taught through English. Internationally, the rise of English-medium instruction (EMI) has led to research on, and discussion about the possible side-effects of a change in instructional language. More specifically, whether using a foreign language as the medium of instruction has a negative impact on teaching and learning. This paper reports the findings of a pilot research project into the implications of English-medium instruction (EMI) as perceived by students and teachers of the bachelor program Commercial Economics at the Faculty of Business, Finance and Administration at THUAS. Research methods used to collect data include face-to-face interviews with both students and lecturers involved in EMI subject courses, a student questionnaire, and lesson observations. Despite regular exposure to English and an adequate self-perceived English proficiency, results show that a considerable number of students, as well as teaching staff are experiencing difficulties with English-medium instruction and that for many EMI is not as efficient in transferring academic content as instruction in the mother tongue.