Heparin-induced thrombocytopenia (HIT) is a disease that causes systemic arteriovenous thrombosis through a series of immune reactions, which leads to multiple organ injury. The purpose of this study was to introduce that diagnosis and treatment of heparin-induced thrombocytopenia with peripancreatic hematoma and high fever in a gastric cancer patient.We reviewed the patient's diagnostic and therapeutic processes.After 25 days of treatment, the platelet count returned to normal, body temperature returned to normal level, and peripancreatic hematoma disappeared.patients with a history of exposure to heparin, patients with fresh thrombosis or spontaneous bleeding of unknown origin should pay attention to HIT screening. We should consider the possibility of HIT when patients have high fever and thrombocytopenia.