Background Postgraduate training is a period in which residents develop both their medical competency and their professional identity in an environment of apprenticeship. As situated learning suggests, a critical dimension of such apprenticeship is the mode through which trainees can legitimately participate in the practice before they become experts, in this case physicians. One source of barriers to participation is cultural difference between learner and the clinical environment. Objective To assess the extent cultural differences create barriers for residents, particularly but not exclusively for international medical graduates (IMGs). Methods In 2014–15 a questionnaire was developed with subscales assessing areas such as sense of hierarchy, individuality versus teamwork, and risk tolerance. We refined the instrument by subjecting it to a review panel of experts in postgraduate education followed by “think aloud” sessions with residents. Results Piloting this instrument yielded a Cronbach’s alpha of 0.675. When administered to a larger group of residents and faculty representing many specialties, the Impact of Cultural Differences on Residency Experiences (ICDRE) questionnaire revealed a few items for which the Canadian Medical Graduates and International Medical Graduates differed in their mean opinion. The groups were not substantially different overall, but we did observe an interesting diversity of cultural beliefs within each group. Conclusions We suggest that the ICDRE may be useful in identifying beliefs which may present challenges to an individual resident or in capturing trends in a resident population so that a specialty program can address the trends proactively. The instrument also provides language with which to anchor preceptors’ evaluations of residents’ professionalism and may serve as an interventional coaching tool. Supplementary Information The online version contains supplementary material available at 10.1186/s12909-021-02548-4.