In the last years, the increasing scientific and industrial interest in Business Process Management (BPM) approaches and methods on the one side, and Internet-of-Things (IoT) technologies and tools on the other. Are these fields complementary? What are their respective interplays and the research challenges to their realizations? The article presents a Systematic Literature Review (SLR) to gain in-depth insights into the maturity of existing approaches to IoT-aware BPM. The analysis of the retrieved studies, framed along the research questions addressed in the SLR, enables us to systematically evaluate the literature on IoT-aware BPM concerning the phases of the process life cycle covered by the different approaches, the specific topics addressed, the application domains involved, and the possibility to tackle the research challenges. Future research directions are also highlighted.