BackgroundMany instruments for evaluating clinical teaching have been developed but almost all in Western countries. None of these instruments have been validated for the Asian culture, and a literature search yielded no instruments that were developed specifically for that culture. A key element that influences content validity in developing instruments for evaluating the quality of teaching is culture. The aim of this study was to develop a culture-specific instrument with strong content validity for evaluating clinical teaching in initial medical postgraduate training in Japan.MethodsBased on data from a literature search and an earlier study we prepared a draft evaluation instrument. To ensure a good cultural fit of the instrument with the Asian context we conducted a modified Delphi procedure among three groups of stakeholders (five education experts, twelve clinical teachers and ten residents) to establish content validity, as this factor is particularly susceptible to cultural factors.ResultsTwo rounds of Delphi were conducted. Through the procedure, 52 prospective items were reworded, combined or eliminated, resulting in a 25-item instrument validated for the Japanese setting.ConclusionsThis is the first study describing the development and content validation of an instrument for evaluating clinical teaching specifically tailored to an East Asian setting. The instrument has similarities and differences compared with instruments of Western origin. Our findings suggest that designers of evaluation instruments should consider the probability that the content validity of instruments for evaluating clinical teachers can be influenced by cultural aspects.Electronic supplementary materialThe online version of this article (doi:10.1186/1472-6920-14-179) contains supplementary material, which is available to authorized users.