Peer evaluation skills are not typically taught to students, yet they are expected to provide high-quality feedback to their peers. Gameful learning, a pedagogy supporting student-driven learning, can further reinforce the development of peer evaluation skills, if students are motivated to improve upon them. To better understand the effects of a peer evaluation training on the quality of student-generated peer evaluations, we scored peer evaluations from two cohorts taking a graduate-level nutritional sciences class using gameful learning pedagogy. The intervention group completed a peer evaluation training before engaging in peer reviews, while the control group did not. The training included two readings, a video, and reflection questions. The peer evaluations submitted by both the intervention and control groups were assessed on a validated rubric. The peer evaluation training had a positive effect on the quality of the submitted peer evaluations. The intervention group had a 10.8% higher score on its first submitted peer evaluation compared with controls (P = 0.003). The intervention group improved the quality of its future submissions by a further 8.9%, whereas the controls did not continue to improve substantially (P < 0.001). Overall, peer review training enhanced the quality of peer evaluations and allowed students to develop professional skills that they can utilize in any biomedical profession. Our results highlight the importance of peer evaluation training in combination with repeated practice and student-driven learning brought forth by gameful learning pedagogy in improving the quality of evaluations and developing professional skills.