It has been proposed that minor oral surgery can be performed safely in patients taking antithrombotic therapy without interrupting treatment; however, there is little evidence-based guidance about how to manage postoperative hemorrhage in patients taking antithrombotics, and few randomized trials that help to inform the risk–benefit ratio of continuing or suspending antithrombotic therapy. The aim of this study was to identify risk factors for postoperative hemorrhage to create a protocol for patients undergoing minor oral surgery with antithrombotic therapy. One hundred and two patients were enrolled, who subsequently underwent 142 minor oral surgical procedures while taking antithrombotic therapy. Demographic details including age and sex, laboratory coagulation investigations, and episodes of postoperative hemorrhage were recorded. The prothrombin time-international normalized ratio (PT-INR) of participants taking warfarin was <3.0 in all cases (mean 1.89 ± standard deviation 0.52; range 1.11–2.82). The activated partial thromboplastin time (APTT) was significantly associated with postoperative hemorrhage, which was significantly increased in patients taking warfarin alone or in combination with an antiplatelet agent compared with an antiplatelet agent alone. In 7 cases, postoperative hemorrhage continued for 4 days and more, requiring additional local hemostatic management. Our findings suggest that minor oral surgery can be performed under antithrombotic therapy without the need of discontinuing the antithrombotic agents. Local hemostatic materials did not suppress postoperative hemorrhage. APTT is a possible prediction factor for postoperative hemorrhage in such patients and, therefore, should be determined prior to minor oral surgery in addition to PT-INR value.