The increase of English-medium instruction (EMI) in higher education has encouraged institutions to provide their academic staff with professional development courses. In this paper, we present the case study of Prof-teaching, a comprehensive EMI teacher training program at a Spanish university with a digital, linguistic and pedagogical approach. The main objective is to determine if the program meets the needs of the institution's current and prospective EMI lecturers. For this purpose, the university context, the key factors that promoted the program, and the objectives and components of its three modules are described. Then, a survey is conducted to gather demographic data and information about Prof-teaching participants' experience, motivation, needs and challenges in relation to EMI. Among the most interesting results was that experienced EMI lecturers claimed that pedagogical training was more important than developing linguistic competence, whereas inexperienced teachers were more concerned with their level of English. In general, the findings of the survey and final course evaluation questionnaires provide evidence of the benefits of the Prof-teaching EMI professional development program. The paper highlights the importance of collaborative efforts among university units to implement EMI teacher training initiatives, as well as conducting periodic needs analysis and quality evaluations. In addition, it is recommended that programs provide lecturers with support technology and that they include mentoring schemes with previously trained EMI content lecturers who already have experience in teaching their subjects in English.