Children with emotional and behavioural disorders (EBD) vary in many respects. In school, specific conditions have to be fulfilled in order to deal adequately with EBD. This study addresses the question how mainstream primary schools design different instructional situations to support pupils with EBD in practice, and how this design could be improved to enhance positive effects on the functioning of pupils with EBD in particular. Theoretically, three sets of educational conditions seem most relevant; the instructional and social-emotional environment, the system of detection and intervention, and the support given to teachers and schools. Case studies were conducted at twelve mainstream primary schools in five different regions in the Netherlands. The results show that the schools focus on providing an adequate social-emotional environment and a corresponding system to detect and manage EBD. However, they lack a coherent pedagogical-didactic structure to integrate diagnosis, special or mainstream curricular levels and materials, and reliable or valid evaluation of social learning results. In addition, they mostly lack a systematic approach to obtaining information from and collaborating with parents and other professionals or external agencies. Specific educational and instructional changes are suggested as concrete possibilities to improve early detection, intervention, and prevention with respect to EBD in mainstream primary schools. (Contains 3 tables.)