Nowadays, oral anticoagulants are commonly prescribed to numerous patients for preventing cardiovascular accident such as thromboembolism. An important side effect of anticoagulant is anti-hemostasis. In a major surgery, the oral anticoagulant therapy (OAT) regimen must be changed before the surgery for proper post-operative bleeding control. However, in a minor dental surgery and endodontic surgery, the necessity for changing or discontinuing the OAT is open to debate. In this study, risks of the consequences were weighed and analyzed. In patients who stop the OAT, the occurrence of thromboembolic complication is rare but the result is fatal. In patients who continuing the OAT, post-operative bleeding can be controlled well with the local hemostatic measures. In the endodontic surgery, there are almost no studies about this issue. The intra-operative bleeding control is particularly important in the endodontic surgery because of its delicate and sensitive procedures such as inspection of resected root surface using dental microscope and retrograde filling. Further studies are necessary about this issue in the viewpoint of endodontic surgery.