The global socio-environmental crisis poses what is arguably the greatest challenge in the history of science. It has demanded an interdisciplinary effort in which thousands of scientists from around the world have rapidly articulated what is already recognized as a consolidated research field: Sustainability science [SS]. Considering the urgency of the matter, it is necessary to evaluate the progress so far achieved. How should this evaluation be carried out? This paper addresses this question taking into consideration some insights from the philosophy of science. In particular, it applies the conceptual framework developed by Thomas Kuhn to the study of scientific paradigms. It first reviews the development of SS, demonstrating that Kuhn’s model is followed step by step. The notion of problem-solving power is discussed as the main criterion for an evaluation of scientific paradigms. Next, several elements are presented suggesting that there is a general insufficiency of problem-solving power in SS. Furthermore, additional empirical data are considered early signs of a paradigm crisis. Subsequently, the way forward for SS is discussed. From Kuhn’s perspective, scientific progress is not only achieved by a steady accumulation of knowledge, but also by episodes of crises that precede radical qualitative leaps in which basic premises are modified. This paper concludes that the urgently needed progress in SS requires engaging in a critical revision of the fundamental claims upon which the field was constructed.