Interdisciplinary research can be defined as the practice of discovering new objects of knowledge beyond disciplinary borders. It often operates through the cross-fertilization and hybridization of concepts, theoretical frameworks, and methodological tools to enable the description, analysis, and understanding of the complexity of objects of study that cannot be reduced to the strict limits imposed by any one discipline. The aim of this article is to take stock of the theoretical and methodological issues involved in the interdisciplinary research process from the perspective of serendipity, which is a creative process of considerable value to science. The intent is to show that the decompartmentalization of disciplines, the ability to decenter and open one's mind to the unexpected are intrinsic to the work of researchers who position themselves between and beyond disciplines. Our contention is that, as a process of discovering with a completely open mind ("sine anticipatio mentis") things that are not being searched for, serendipity is thus capable of playing a central role in interdisciplinarity, boosting the exchange of ideas and speeding up their circulation among researchers committed to exploiting the heuristic dimension of the unexpected.