To investigate perioperative and postoperative bleeding, complications in patients under therapy with anticoagulant or antiplatelet drugs submitted to oral surgery. To evaluate the risk of bleeding and safety for dental surgery, a retrospective chart review was performed. Medical and dental records of patients taking oral antithrombotic drugs undergoing dental surgery between 2010 and 2015 were reviewed. Results were statistically analyzed using Fisher's exact test, t test or the χ2 test. One hundred and seventy-nine patients underwent 293 surgical procedures. A total of eight cases of perioperative and 12 episodes of postoperative bleeding were documented. The complications were generally managed with local measures and did not require hospitalization. We found significant association of postoperative hemorrhage with increased perioperative bleeding (P = 0.043) and combination of anticoagulant and antiplatelet therapy (P < 0.001). The chance of postoperative hemorrhage for procedures with increased perioperative bleeding is 8.8 times bigger than procedures without perioperative bleeding. Dental surgery in patients under antithrombotic therapy might be carried out without altering the regimen because of low risk of perioperative and postoperative bleeding. However, patients with increased perioperative bleeding should be closely followed up because of postoperative complications risk.