Professions in general, and project management in particular, are undergoing a deep change towards the integration of sustainability concepts into their core values and practices. ‘Sustainability’ itself increases the number of tensions and constraints professionals experience in their everyday work. We will discuss how the presence of organizational barriers, the different temporality of sustainable objectives, and the lack of power, knowledge, and support are among the factors that lead project managers to favour win-win solutions. We conclude presenting also the possibility that project managers could embrace the inherent contradictions of sustainability objectives and develop a more ‘paradoxical’ approach.