In addition to common dysfunction of the brain and kidney, thrombotic thrombocytopenic purpura (TTP) may present with atypical clinical features due to the involvement of other organs such as the lung, pancreas, heart, eye, and skin. We have also observed the unusual presentation of peripheral digit ischemic syndrome (PDIS) in some patients with postoperative TTP To clarify this relationship between TTP and PDIS, the hematologic data from the medical records of patients with known diagnoses of thrombotic microangiopathy (TM) were examined in a single institution. A total of 94 patients were diagnosed with TM. Among these patients, PDIS developed in six patients and in all these patients PDIS occurred with postoperative TTP Four patients also had acute respiratory distress syndrome (ARDS). Because of delayed diagnosis of TTP, only two patients survived and four died. One patient responded to plasma exchange and survived, and another patient recovered from postoperative TTP without plasma exchange. However, both patients required the amputation of multiple digits. In conclusion, PDIS is another atypical manifestation of TTP and has occurred exclusively in patients with postoperative TTP in this series. Once PDIS developed, the prognosis was poor and amputation of digits was needed in surviving patients. Early recognition of this atypical manifestation of TTP is essential for a favorable outcome.