Background: Little is known about simulated students' ability in assessing feedback received in Objective Structured Teaching Encounters (OSTEs). We aimed to assess to which extent students' perceptions matched objective analysis regarding quality of received feedback, to explore what elements of feedback they emphasized and what they learned about feedback.Methods: In this mixed-method study, 43 medical students participated as simulated residents in five OSTEs at Geneva University Hospitals. They assessed quality of feedback from faculty using a 15-item questionnaire and gave written/oral comments. Videotaped feedbacks were assessed using an 18-item feedback scale. During four focus groups, 25 students were asked about what they learned as feedback assessors.Results: 453 students' questionnaires and feedback scale were compared. Correlations were moderate for stimulating self-assessment (0.48), giving a balanced feedback (0.44), checking understanding (0.47) or planning (0.43). Students' feedback emphasized elements such as faculty's empathy or ability to give concrete advice. They reported that being a feedback assessor helped them to realize importance of making the learner active and that giving effective feedback required structure and skills.Conclusion: Medical students may identify quality of feedback. Involving them in OSTEs could be interesting to train them to become valid raters of supervisors' teaching skills.