This longitudinal study examines connections between 110 teachers' perceived professional competence acquired during professional preparation and later perceptions as schoolteachers in Norway. The results indicate that theoretical understanding plays an important role in schoolteachers' professional competence development and that prospective and practising schoolteachers do not tend to perceive themselves as either good theorists or good practitioners. Furthermore, the results contradict research arguing that the teacher education programme has limited effect. Instead, the results indicate that the level of perceived competence acquired during professional preparation in the general teacher training programme is of major importance for perceived mastery of teaching as a schoolteacher. In addition, the results also underscore the importance of experiencing continuing mastery of teaching requirements for supporting perceptions of teaching specific self-efficacy over time. This finding again supports previous research that has emphasised the importance of supporting teaching specific self-efficacy during both the period of teacher education of prospective teachers and the induction period of newly qualified teachers.