Destro MWB et al. Hematoma after augmentation mammaplasty in a patient with von Willebrand's disease Hematoma após mamaplastia de aumento em paciente portadora de doença de von Willebrand ABSTRACT We present the case of a patient submitted to augmentation mammaplasty who developed 2 hematoma episodes as a result of von Willebrand's disease, which was not previously diagnosed. As a routine part of preoperative evaluation, the patient should always be tested for von Willebrand's disease. This disease affects 1-3% of the population and occurs twice as often as hemophilia. In our case, the patient recovered quite satisfactorily. Preventive and therapeutic approaches are discussed in this paper.