Purpose To determine how closely institutional review board (IRB) discussions reflect the ethical criteria specified in the Common Rule federal regulations Method Between November 2006 and July 2009, the authors observed, audio-recorded, transcribed, and coded protocol reviews from 20 IRB meetings at 10 leading academic medical centers. They also reviewed each of the applications discussed to identify the Common Rule criteria--(1) risk minimization, (2) risk/benefit comparison, (3) equitable subject selection, (4) informed consent, (5) data monitoring to ensure safety, (6) privacy protection and confidentiality, and (7) protection of vulnerable subjects--that were both relevant to the study and not adequately addressed in the application. They then determined if the IRB addressed each of the relevant and not discussed Common Rule criteria in their discussions. Results IRBs made no mention of many of the Common Rule criteria that required their discussion--in 17/82 (21%) reviews, they failed to address risk minimization; in 52/91 (57%), risk/benefit comparison; in 31/52 (60%), equitable subject selection; in 32/59 (54%), data monitoring; in 13/52 (25%), privacy and confidentiality; and in 7/55 (13%), protection of vulnerable populations. However, they discussed informed consent in 102/104 (98%) reviews and raised questions about, or requested changes about, informed consent for 92/104 (88%) protocols. Conclusions These findings suggest that essential elements of human subjects protection are not implemented uniformly across IRBs. While not directly addressing this issue, the current proposed changes to the Common Rule offer an opportunity to improve, in general, the effectiveness of IRBs to protect human subjects.