The present work investigates professional self-concept domains of pre-service teachers of the teaching degree programs 'Teaching at Elementary Schools' and 'Special Education' in two different studies. The first study investigates whether and to what extent pre-service teachers' professional self-concepts - with regard to planning and implementing inclusive education and cooperation with colleagues - can be fostered by a university-based learning unit on teacher cooperation in the inclusive classroom. In the second study, differences in the development of pre-service teachers' self-concepts are examined in relation to their type of tandem compositions (freely selected tandems vs. randomly assembled tandems) for the planning and implementation of inclusive lessons in elementary schools.