To deal with world-wide problems in development, actors need to co-create new knowledge. This can be done through mutual reflection on underlying values and assumptions and by combining the knowledge of different actors from society and academia. This paper shows how knowledge co-creation can be facilitated with attention to multiple actor collaboration, creating outputs which are relevant for science and society and which contribute to sustainable development. We describe how a group of different actors can become mutually engaged to co-create knowledge in a shared domain of interest. Through mutual learning and experimentation in a community of practice, the actors develop a shared repertoire of socially robust knowledge. The balance between theory and practice during knowledge co-creation process helped to gain in-depth understanding of the process. This shows the importance of mutual learning and co-creation of knowledge when a new issue is introduced in development practices. To illustrate this, the experiences of over 30 organisations, united in a community of practice on disability inclusive development, are considered.