Objective: The aim of this study was to investigate preceptors' and nursing students’ experiences of peer learning in a psychiatric context during their clinical education. Design: A qualitative research design was used in this study. Data were analysed with qualitative content analysis. The study was conducted in 2017 with 17 preceptors and 11 students, constituting four focus groups with preceptors and four focus groups with nursing students. Participants: The preceptors were nurses and specialist nurses who worked in inpatient psychiatric care. Nursing students seeking their bachelor's degrees were placed in clinical settings at different psychiatric units for 4 weeks during the fourth semester. Results: One theme emerged: Knowledge acquisition as an interactive process from the two shared categories for students and preceptors: reciprocal learning by communication, doing and reflection and the importance of a supportive relationship. Conclusions: The result of this study suggested that peer learning in clinical education in psychiatric care promoted the learning process for nursing students.