Being a professional teacher involves developing professional agency. Among the important standards of professional agency is the ability to justify classroom practices in light of conceptual knowledge and transformative reflection and clarify personal commitments and intentions in decision-making processes. This study explored how 12 student teachers participating in a teacher education programme in Norway revealed their sense of professional agency while sharing their thoughts about their commitments, intentions, and experiences regarding teaching and mentor support when practising teaching in schools. The study used semi-structured interviews. The student teachers revealed a strong sense of professional agency and a strong intention to develop this agency. However, the practice context did not seem to support them in exploiting their capacity to develop professional agency. Consequently, studies and discussions on how the practice context helps student teachers in their professional learning are required.