Given the complexity of current social structures and environmental problems, attaining a truly sustainable society seems rather improbable today. Not only has society not been planned for the complexity of the preconditions and effects that sustainability entails, sustainability is also unlikely given current individual consumption patterns, prevailing economic worldviews, and the short-term focus of political processes. In this context, transdisciplinary research is seen more and more as key to attaining social change towards sustainability. In order to do this, non-academic actors must be extensively involved in knowledge production, and normative considerations have to be explicitly incorporated. This paper targets three key areas for discussion. These are participation, value rationality and mutual learning. The interactions of participation and value rationalities through mutual learning processes are developed through two examples of ongoing transdisciplinary research and collaboration in Western Sweden. (Contains 5 notes.)