The suggested system of teacher certification is intended, by the government, to increase the professionalism of teachers and to contribute to the overall professionalization of teaching. However, sociologists of professions claim that professionalism in resent years, as it becomes attached to ever more occupational groups, has become an effective discourse of organizational control used in order to govern deregulated or decentralized systems from a distance. Following this, the article argues that the system of certification is part of an ongoing reprofessionalization of Swedish teachers. As part of the state’s growing number of external control mechanisms surrounding the work of teachers, the system of certification is argued to contribute to a process in which the work of teachers is changed in line with the perceived demands of a knowledge economy in which effectiveness, competition and accountability are central values. As a result, what it means to be a teacher is slowly changing in the process of educational reform, contributing to the uncertainty expressed by Swedish teachers as to what it is they are supposed to achieve.