The incidence of von Willebrand disease in the Netherlands is unknown, but the occurrence of all types of von Willebrand disease together is estimated at 1:100-1:200 individuals. Most patients have mild von Willebrand disease, mostly type 1. For the more severe forms of von Willebrand disease the incidence in unclear, but the expectation is, that there are at least 500-1500 patients. In the Netherlands, an unique situation exists for the treatment of patients with hemophilia and related coagulation disorders. In 2000 a hemophilia management policy was set up by the Ministry of Health, which stated that the care for these patients should be concentrated in 13 Hemophilia Treatment Centers (HTC). The representatives of the attending centers, the hemophilia specialists, are organized in the NVHB, the Dutch society of Hemophilia treaters. In the hemophilia management policy is stated that all patients with a coagulation disorder dependent of replacement products must be treated in a HTC or under responsibility of a HTC. These patients are seen in a HTC at least once a year.