Background Diversity in Institutional Review Board (IRB) membership is important for both intrinsic and instrumental reasons, including fairness, promoting trust, improving decision quality, and responding to systemic racism. Yet U.S. IRBs remain racially and ethnically homogeneous, even as gender diversity has improved. Little is known about IRB chairpersons’ perspectives on membership diversity and barriers to increasing it, as well as current institutional efforts to promote diversity, equity, and inclusion (DEI) within IRB membership.Methods We surveyed IRB chairpersons leading U.S. boards registered (...) with the Office for Human Research Protections. Here, we focus exclusively on responses from a subset of 388 chairpersons of IRBs at universities and academic medical centers (AMCs).Results Board chairs were predominantly white and evenly split between men and women. Only about half reported that their boards had at least one member who is Black or African American (51%), Asian (56%), or Hispanic (48%), with 85% of university/AMC boards comprised entirely (15%) or mostly (70%) of white members. Most IRB chairpersons (64%) reported satisfaction with the current diversity of their membership. Participants largely agreed that considering diversity in the selection of IRB members is important (91%), including to improve the quality of IRB deliberation (80%), with an emphasis on racial/ethnic (85%) and gender diversity (74%). Most participants (80%) reported some type of active DEI effort regarding board membership at their university/AMC and just over half (57%) expressed satisfaction with these efforts.Conclusions Our national survey found that although university/AMC IRB chairpersons report valuing diversity in board membership, it may be lacking in key areas. Going forward, it will be important to specify clear reasons for diversity in the IRB context, as well to establish targets for acceptable levels of board diversity and to match DEI efforts to those targets. (shrink)