Long-term planning with a time-horizon beyond 20 to 30 years is an established element of policymaking in some core fields such as certain infrastructure policies, and is a substantial principle of sustainable development. At the same time short- and medium-term planning is much more usual in the search for ad-hoc solutions to environmental, economic and social challenges. Economic actors apply flexible policies and use short-term opportunities for their profit. Environmental and social problems also sometimes imply short-term solutions for the survival of a system in acute danger. This creates a paradoxical situation: the society in question needs to define long-term targets for its infrastructure and achieves systematic changes pursuing those, but the necessary short-term actions and flexibility applied to stay functionable might not be in line with longterm goals. If this apparent paradox cannot be solved through an appropriate governance method, it might lead to a conflict between different policy goals. The concept of reflexive governance for transition management tries to solve this apparent paradox and combines a number of short-term planning processes in a stagewise and reflexive way to create a more comprehensive and innovative process of long-term planning for a sustainable development. Future-oriented analyses and forward-looking activities are a fix element at each stage. This contribution points out some key questions for a flexible long-term planning process within the framework of sustainable development. The main challenge is how different knowledge types such as citizens’ visions and experts’ recommendations can be integrated into long-term planning in order to support an interactive decision-making process that considers a broader basis of information. CIVISTI, an innovative forward-looking approach, addresses this challenge. The CIVISTI method has been developed during the recent EUproject on Citizen Visions on Science, Technology and Innovation (CIVISTI 2008-2011). In this paper we introduce and discuss this method as a reflexive instrument for integrating different types of knowledge and creating a bridge between short- and long-term planning.