Problem-based learning (PBL) involves using problems as a starting point of learning rather than relying on traditional learning settings. In the present paper we present the theoretical framework behind a specific PBL setting we have developed since 2012 for training Danish psychologist students in a small university children's clinic (Børnesprogklinikken) at Aalborg University, Denmark. We argue that our approach can serve as students' enculturation into a specific profession, and that concepts from the theory of cultural learning and the concept of mediation can elucidate why this type of learning is effective for human beings, and specifically for students learning a profession. Finally, we discuss some of the learning outcomes of the PBL programme.