Research evidence from several educational systems indicates that students with developmental disabilities who exhibit challenging behaviors are in the bottom of the agenda as candidates for inclusion. The present investigation of the perspectives of 85 Greek teachers in primary education indicates that they are in need of training that it will enable them to deal with the presence of a student with challenging behaviors in their classroom and that it will assist them to overcome their concerns about the impact of inclusion of students with challenging behaviors on their time and emotional well-being, the routine of the class, the peer acceptance and the educational progress of the student with challenging behaviors. The implications for training are briefly discussed.