In compliance with the necessities of sustainable development, planning tools have to integrate qualitative criteria for development and pursue a new, collaborative decision-making logic. Performative planning as an action-oriented method is introduced here as an instrument of collaborative planning. It derives its concepts from the performance art movement initiated by John Cage in the 1940s. Considering the example of the experimental planning project for revitalising the city core in Dessau, a shrinking city in Eastern Germany, the possibilities and limits of such an approach are discussed