This paper describes and analyses the potentials and limits of Design Thinking in Sustainability Jams, claimed increasingly to contribute sustainability solutions and changed practices for desired futures. With an in-depth Case study, we show how the current application of “Design Thinking” coming from the management context (where Design Thinking is deployed as a human-centred problem-solving approach) can impair the idea of a Sustainability Jam and where this event format must be questioned. Design Thinking and Jamming are found to offer promising tools and frameworks to generate possibilities for sustainable futures, yet the case study demonstrates how this potential is squandered. Our empirical results point to several limitations in the practice of a sustainability jam: User-orientation, the use of personas and prototypes, insufficient complexity and insufficient embodiment hinder the potential of design thinking to foster social creativity and to address wicked problems of sustainability. We suggest directions in which to understand and eventually overcome these limitations, toward redesigning sustainability jams in order to better fulfil their promises.