<p>Teachers often feel insufficiently prepared for inclusive education, especially when it comes to working with students with emotional and behavioral difficulties (EBD). For higher education, the question arises of how inclusion can be systematically integrated as a cross-cutting theme in teacher education curricula and how the development of professional competence can be supported. One possible approach is interdisciplinary co-teaching, where different disciplinary perspectives are combined and students are encouraged to integrate this knowledge. The present study investigates, in a quasi-experimental pretest–posttest control group design with 122 primary teacher education students, the effects of two forms of co-teaching on inclusion-related beliefs and knowledge about the design of inclusive teaching for students with EBD. In the experimental condition, co-teaching by a tandem of lecturers in general and special education took place in both the preparation and implementation of the course. In the control condition, the lecturers jointly prepared the course, but delivery was carried out solely by the general education lecturer. The results show that co-teaching in both preparation and implementation had a positive effect on the perception of challenging student behavior but no effect on lesson planning. With regard to beliefs, differentiated effects emerged, including some that were more negative. These findings are discussed in light of the challenges of teacher education and provide initial insights into the opportunities and limitations of co-teaching for student learning processes.</p>