Background Research codes of conduct offer guidance to researchers with respect to which values should be realized in research practices, how these values are to be realized, and what the respective responsibilities of the individual and the institution are in this. However, the question how the division between individual and institutional responsibilities is to be made, has hitherto received little attention. Therefore, we conduct an analysis of research codes of conduct, and investigate how responsibilities are positioned as individual or institutional ones and how the boundary between those two is shaped.Method We selected 12 codes of conduct that apply to medical research in the Netherlands, and performed a close-reading content analysis of these codes of conduct. We first identify dominant themes, and then investigate how responsibility is attributed to individuals and institutions.Results We observe that in many cases, the attribution of the responsibility to either the individual or the institution is not entirely clear and that the notion of culture appears as a residual category for such attributions. This notion of responsible research cultures is deemed important as something that mediates between the individual and institutional level, but at the same time largely lacks substantiation.Conclusions While many attributions of individual and institutional responsibility are clear, the exact boundary between individual and institutional responsibility is often problematic. We suggest two possible avenues for improvement in codes of conduct: either clearly attribute responsibilities to individuals or institutions and depend less less on the notion of culture, or make culture a more explicit concern and articulate what it is and how it could be fostered.