Thrombin generation assay (TGA) is a tool to assess bleeding and thrombotic risk in citrated plasma, either in the presence or absence of platelets, and several different commercial assays have been developed and actively marketed. TGA can be used for various research and clinical applications, including the identification of patients at risk of bleeding or thrombosis, as well as monitoring of treatment in at risk patients. Though current implementation is limited to specialized laboratories in university hospitals and research centers, wider implementation will require additional, large clinical trials.