The metalloproteinase ADAMTS13 (a disintegrin with a thrombospondin type 1 motif, member 13), also known as VWF (von Willebrand factor) protease, may be assessed in a vast array of clinical conditions. Notably, a severe deficiency of ADAMTS13 characterizes TTP (thrombotic thrombocytopenic purpura), a rare but potentially fatal disorder associated with thrombosis due to accumulation of prothrombotic ultra-large VWF multimers. Although prompt identification/exclusion of TTP can be facilitated by rapid ADAMTS13 testing, the most commonly utilized assays are based on ELISA (enzyme linked immunosorbent assay) and require long turnaround time and have relatively limited throughput. Nevertheless, several rapid ADAMTS13 assays are now available, at least in select geographies. The current mini-review discusses these issues, as well as the potential utility of ADAMTS13 testing in a range of other conditions, including coronavirus disease 2019 (COVID-19).