What treatment is appropriate for a patient who has to undergo an invasive dental procedure if that patient is using medication that influences the blood coagulation system? Should the medication be stopped before the invasive procedure, with the risk of complications involving re-thrombosis? Or should the procedure be carried out without adjusting the medication? What is the risk of bleeding complications? Recent studies appear to indicate that temporarily stopping medication is in many cases unnecessary and can even harm the patient. In recent decades dentists have received a great number of diverse recommendations. In this article recent research in this field is summarized and evaluated. The authors advocate the development of evidence-based clinical guidelines.