An active approach allowed undergraduates in Health Sciences to learn the dynamics of peer review at first hand. A four-stage process was used. In "stage 1", students formed self-selected groups to explore specific issues. In "stage 2", each group posted their interim reports online on a specific date. Each student read all the other reports and prepared detailed critiques. In "stage 3", each report was discussed at sessions where the lead discussant was selected at random. All students participated in the peer review process. The written critiques were collated and returned to each group, who were asked to resubmit their revised reports within 2 wk. In "stage 4", final submissions accompanied by rebuttals were graded. Student responses to a questionnaire were highly positive. They recognized the individual steps in the standard peer review, appreciated the complexities involved, and got a first-hand experience of some of the inherent variabilities involved. The absence of formal presentations and the opportunity to read each other's reports permitted them to study issues in greater depth. (Contains 2 tables and 4 figures.)