Peer feedback is crucial for the continuous development of (pre-service) teachers’ professional competence. To foster peer feedback competence effectively, research needs to determine which components of pre-service teachers’ professional competence (e.g., professional vision/knowledge/beliefs) predict peer feedback quality. To date, this relationship has not been analysed. The study covered in this chapter investigated to what extent pre-service teachers’ professional vision, knowledge, and self-efficacy beliefs determine the quality of their peer feedback. Professional vision, knowledge, and self-efficacy beliefs were measured, and pre-service teachers provided written feedback for a video-based classroom management situation. Written feedback was analysed with an adapted version of the Feedback Quality Index (e.g., specificity, quality of questions). Multiple regression analyses showed that both pre-service teachers’ professional vision and knowledge of classroom management positively predicted peer feedback quality concerning its specificity. Furthermore, pre-service teachers’ professional vision positively predicted quality of questions, while pre-service teachers’ self-efficacy beliefs displayed a negative relationship to quality of questions. The results indicate that teacher education should focus on promoting pre-service teachers’ professional vision and knowledge and make the importance of questions apparent to self-efficacious pre-service teachers in peer feedback trainings, to increase peer feedback quality.