The need to support those teaching in English-medium instruction (EMI) classrooms is becoming increasingly acknowledged, and faculty professional development (PD) is recognised as an important element of that support. This study, a replication and localisation of an international study by Macaro et al. (2020. "English Medium Instruction in Higher Education: Teacher Perspectives on Professional Development and Certification." "International Journal of Applied Linguistics" 30 (1): 144-157), investigates the experiences and attitudes of faculty members teaching in EMI programmes in South Korea and Japan towards EMI related PD and certification. Survey findings (South Korea n = 234, Japan n = 92) indicate that few faculty members have experience with pre-service PD, and that EMI-related in-service PD is rare in South Korea but on the rise in Japan. Preferences for PD and attitudes towards certification differed between the two populations sampled, and there are indications that the disciplinary and language backgrounds of the professors may influence this. This highlights the need for local, context-appropriate approaches to supporting faculty in EMI programmes.