Abstract Oral surgery—mainly tooth extractions—was performed on patients with hemophilia A, hemophilia B, and von Willebrand's disease. They were treated with only one transfusion of factor VIII or factor IX concentrate, which was given immediately before the operation. During the time of treatment, Cyclocapron was administered in doses of about 25 mg. per kilogram of body weight every 6 hours. With this method it was possible to extract more teeth at one time without bleeding complications than had been the case previously. It was also shown that the patient's stay in the hospital could be reduced considerably.