The effectiveness of a commercial drug containing fibrinogen, thrombin and factor XIL (Tissucol, Immuno) was assessed in 127 patients receiving oral anticoagulant treatment with acenocoumarin who were subjected to 183 minor surgical procedures: 107 exodontia, 53 periodontal procedures, 17 combinations of the former, 4 liver biopsies and 2 skin biopsies. All but the liver biopsies were performed in the outpatient clinic. Mild haemorrhage appeared in 21 instances. None of the patients required systemic administration of coagulation factors, and the maneuvers did not take any longer than in patients with integrity of the coagulation mechanisms. The outstanding benefits of this technique are: less discomfort for patients, who can be subjected to a single procedure while otherwise requiring several sessions; anticoagulation needs not be discontinued, subcutaneous heparin being otherwise necessary; low risk of complications and avoidance of substitutive therapy; lesser economic burden, as no hospital admission is needed.