Undergraduate research is a challenging environment for supervisors and students and the current climate of cultural diversity in higher education and medical faculties means supervisors may have responsibility for English as Second Language (ESL) Asian students. The Bachelor of Medical Science (BMedSci) is a well-established context for undergraduate research projects and is the context in this study for examining the challenges for supervisors. Methods: Semi-structured interviews were conducted with twenty-seven academics in an Australian university with experience of supervising Indonesian medical students, which gathered supervisor perceptions of the challenges of supervising international students as compared to supervising their Australian peers. Results: Interviews and data analysis generated themes regarding culture and the individual, comprehension and feedback, disciplinary differences, developing knowledge, language and conceptual clarity, education and critical analysis. Discussion: Academic supervisors hold a nuanced view of the challenges to and benefits of supervising International ESL students compared to their Australian peers. Supervisor experience, funding and purpose of the year remain issues to be investigated in future studies.