It seems that every few years concerns are raised about the practice of pathology peer review, even though peer review has been part of toxicologic pathology since the late 1970s. While the individual procedures have varied slightly, the overarching intent of pathology peer review has been to provide diagnostic consistency and accuracy of interpretation of the pathology data to the global regulatory authorities to aid in their decision making regarding the safety of biopharmaceuticals and chemicals. The intent of peer review is not what raises periodic cause for concern among regulators, but rather other technical aspects of the process that surface periodically. That is why we believe that worksheets should be retained even though this step is not ‘‘required’’ or espoused by Society of Toxicological Pathology (STP; Morton et al. 2010). Kerlin (2012) briefly touched on some of the perceived reasons behind issues with peer review in his Regulatory Forum Opinion Piece on pathology raw data. Often times the ‘‘documentation’’ of the peer review is regarded as pathologist’s ‘‘interim notes’’ and are discarded after the report is completed, as these ‘‘notes’’ are not deemed to be necessary for the reconstruction of the pathology evaluation. While this practice may be expeditious in completing the peer review and reduces retained documents, it can be perceived as a ‘‘black box’’ around the peer-review process and opens the study for criticisms relative to data integrity and manipulation of data. While pathologists have long stated that peer review is intended to ensure the quality of the pathology evaluation in safety studies (Ward et al. 1995; Boorman et al. 2010), it does no good if the process used creates doubt in the skeptical mind of compliance and regulatory authorities relying on the final evaluation and interpretation of the data. It has previously been suggested that the peer review worksheets could be included as an appendix to the pathology report or maintained in the study file (Ward et al. 1995). Long (1996) and Mann (1996) continued to stress the need for a well-documented peer review process to give regulatory reviewers greater confidence in the pathology evaluation. However, a recent commentary by McKay et al. (2010), based upon current practices in the United States, European Union, and Japan, restated the position that peer review worksheets are not raw data and do not need to be retained or submitted. The issue is not what constitutes raw data and what should be retained, but instead the issue is one of transparency in the process. The latest controversy has focused not on the raw data but on the integrity of the data generated by the study pathologist. This is not a new issue, as Peters (1996) has already highlighted the need to maintain peer review worksheets to add credibility to the process and to ensure that the recommended data changes as a result of the peer review were made. More recently, a series of Food and Drug Administration (FDA) compliance inspections and interactions with agency representatives both in the United States and in Europe have questioned the timing of when the database should be ‘‘fixed or locked.’’ The ‘‘influence’’ by the sponsor and/or the peer review pathologist on the study pathologist’s findings has raised concerns on the part of regulators regarding how to maintain the integrity of the database. This has led to a recommendation from compliance inspectors that pathology data be locked prior to the peer review in order to track changes made during or after the peer review. The concerns raised by the regulators distill to transparency of the peer-review process. Although STP has provided *This is an opinion article submitted to the Regulatory Forum and does not constitute an official position of the Society of Toxicologic Pathology or the journal Toxicologic Pathology. The views expressed in this article are those of the authors and do not necessarily represent the policies, positions, or opinions of their respective agencies and organizations. The Regulatory Forum is designed to stimulate broad discussion of topics relevant to regulatory issues in toxicologic pathology. Readers of Toxicologic Pathology are encouraged to send their thoughts on these articles or ideas for new topics to regulatoryforum@toxpath.org. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author(s) received no financial support for the research, authorship, and/or publication of this article. Address correspondence to: Jeffery A. Engelhardt, EPL, Inc., 5407 Castillo de Rosas, Camarillo, CA 93012, USA; e-mail: jengelhardt@epl-inc.com. Abbreviations: FDA, Food and Drug Administration; QC, quality control; STP, Society of Toxicological Pathology.