The article discusses internships at the end of longer professional university studies. The empirical material is taken from a larger project about newly educated clergy in Denmark, Norway and Sweden, which follows them from the last term of their education and three years into their ministry. The article builds on focus groups and individual interviews that thematize internship periods, with an emphasis on experiences of mastery and shortcomings in these. The research question concerns how practice periods can be understood as learning arenas, and what conditions enable and limit professional learning in these activities. Similarities and differences between the countries helped to identify three critical tensions in the facilitation of internships: the relationship between practising the professional role and the internship role, the relationship between doing professional tasks and developing one’s professional identity, and the tension between preparing to become a professional and conducting professional work. These three findings are elaborated and discussed using perspectives from liminality theory and boundary theory. The article nuances the understanding of internships as liminal zones, and shows how different learning mechanisms open and close the students’ movement between study and profession. We also discuss the importance of the supervisor’s positioning, and the complexity of the relationship between professional tasks and professional role.