Assessment and feedback guide learning. In light of this, the assessment practices of teacher education have received little research. This qualitative study examines student teachers' discussions in a study unit built on authentic assessment practices: self- and peer assessment of videotapes from authentic performance with research-based rubrics. The aim is to investigate whether authentic assessment supports student teachers' reflection and, if so, how. The findings show that authentic assessment led students frequently to reflection, and in most cases reflective discussions were induced by students' self-criticism. We deduced that the encouraging feedback culture between students and between students and the teacher enabled students to be open about their self-critical observations. According to the findings, building a study unit on authentic assessment is a promising way to guide students to reflect on theory and practice and to learn skills that are essential for their future profession.