Context: Peer assessment is widely used in medical education as a formative evaluation and preparatory tool for students. Athletic training students learn similar knowledge, skills, and affective traits as medical students. Peer assessment has been widely studied with beneficial results in medical education, yet athletic training education has thus far produced only 2 studies that address the use of peer assessment with athletic training students. Objective: To identify whether undergraduate athletic training students accurately and reliably assess their peers on clinical skills and professional behaviors. Design: Quasi-experimental between-groups and within-group. Setting: Medical exam office. Patients or Other Participants: Junior and senior athletic training students, classroom faculty and clinical preceptors (instructors) from the same Commission on Accreditation of Athletic Training Education athletic training program. Intervention(s): One instructor and 2 students concurrently performed an assessment in real-time of 5 clinical skills performed by a junior or senior student. Clinical skills demonstrated were the Biceps Femoris Manual Muscle Test (BFMMT), Lachman Test, Kleiger Test, Noble's Compression Test, and Thompson Test. Main Outcome Measure(s): Each student group's scores were compared with instructor group scores to determine the accuracy of the assessment. Each student group's scores were compared within-group to determine reliability of student scores. Accuracy and reliability of clinical skills were measured using the Cohen ? coefficient. A weighted Cohen ? coefficient was used for professional behavior measures. Results: Senior students were accurate (P < 0.05) for all clinical skills and professional behaviors and reliable (P < 0.05) for the BFMMT, Thompson Test, and professional behaviors. Junior students were accurate (P < 0.05) for all clinical skills except the Lachman Test and reliable (P < 0.05) for the BFMMT and Noble's Compression Test. Conclusions: Students are able to assess the clinical skills of their peers with the same consistency as instructors during a live skills demonstration. Year in school may affect ability to assess professional behaviors.