Intravenous adrenalin infusion (5 μ g/kg, at most 160 μg in 10 min) normalized partial thbromboplastin time (PTT) and ristocetin induced platelet aggregation (RIPA) in 4 of the 14 patients with von Willebrand’s disease (VWD) in a short period of time. Although mean factor VIII (F-VIII) procoagulant activity was almost doubled 5 min following infusion, this was mainly observed in patients with relatively high baseline ( > 2%) AHF activity. Mean F-VIII procoagulant activity rose by more than 100% following 10 days of corticosteroid treatment (deltacortil 2 mg/kg/day, at most 60 mg/day). PTT became normal in 6 of the 11 patients, but RIPA normalized only in 2. The improvement of RIPA did not correspond to bleeding time in every patient. These results may suggest that if the baseline AHF activity is relatively high ( ≥ 9.5%), corticosteroid could be tried before schedule surgical intervention in patients with VWD.