This article reports on findings from a research project on interdisciplinary collaboration between mainstream school teachers and special school teachers. The aim of the research project has been to examine the knowledge of special school teachers and how this knowledge can contribute to the development of an inclusive learning environment in mainstream schools. Not as a simple task of transferring knowledge, but as a process of transforming knowledge through interdisciplinary collaboration and co-teaching. The design of the study is inspired by the notion of participation within action research as a research approach. Thus the thick data generated from reflective activities in the study design are analysed within a narrative and practice directed strategy of analysis.