Autoantibodies against coagulation factors can develop in patients associated with autoimmune disorders, malignancies, pregnancy, and drug-induced or dermatological diseases. These antibodies can bind to functional epitopes of individual coagulation factors, neutralize their activity or promote their clearance, and clinically leading to bleeding conditions. Among them, the most common one is that directed against factor VIII (FVIII). Patients with autoantibodies against FVIII often have severe hemorrhage and delayed diagnosis can contribute to high mortality in these patients. Further, autoantibodies against other coagulation factors, such as Factors V, XI, XII, XIII, and the vitamin-K dependent proteins, occur more rarely. The pathogenesis for developing autoantibodies against these coagulation factors is still unclear. A mechanism of breakdown in immune tolerance, which may be derived from a combination of genetic and environmental factors as well as the aging of the immune system in elderly individuals, may be responsible for the development of autoantibodies against FVIII. In this article, we reviewed and updated the classification and diagnostic algorithm for identifications of autoantibodies against the coagulation factors in clotting cascade.