Many countries are moving towards more inclusive education. Yet there is only little evidence on the effect of moving students with special educational needs from segregated educational settings to regular classrooms on students' medium-term outcomes like enrolment in upper secondary programmes. This study contributes to filling this gap using combined evidence from matching and instrumental variable approaches. The results suggest that mainstreaming students substantially increases enrolment and progress towards the certificate. Earlier mainstreaming tends to be more effective. Academic skills at the end of compulsory schooling are identified as an important mediator.