Work Integration Social Enterprises (WISE) are a particular enterprise form permeated by a so-called ‘double business idea’. Besides the commercial imperative of providing product and services, WISE offer employment and training opportunities for individuals considered less able to compete in mainstream labour markets. The paper argues that this multiple goal structure makes WISE an ideal testbed for Challenge-Based Learning (CBL). The latter deepens both problem-based learning and CDIO, by featuring open-ended problems that stress an entrepreneurial, value-driven and sustainable approach to problem formulation and decision-making. The aim of this paper is to describe how real-life design projects conducted in collaboration with WISE take CBL a step forward compared with those involving more ‘traditional’ enterprise forms. Evidence is gathered along 4 main lines of thought, which are: 1) iterative problem formulating and designing; 2) entrepreneurial mindset and of value-driven learning; 3) social sustainability-aware designing; and 4) social-constructed learning. The findings indicate that WISE-based design experiences bring forward additional characteristics compared with more ‘traditional’ engineering ones. Students are able to expand the scope and depth of their problem identification and formulation activities, due to the continuous dialogue with a broad range of stakeholders, enthusiasts, and volunteers. They become more aware of the multifaceted meaning of the word ‘value’ in engineering, realizing the existence of competing value systems for the design problem. Eventually their decision-making activities emphasizes the pursuit of different goals and objectives (e.g., technical feasibility, business viability, and sustainable development) in the design process.