The reported underlying lymphoproliferative disorders associated with acquired von Willebrand disease (AvWD) include benign monoclonal gammapathy, multiple myeloma, Waldenström disease, chronic lymphocytic leukemia, non-Hodgkin lymphoma, and hairy cell leukemia. The AvWD in patients with a monoclonal gammapathy and/or a lymphoproliferative disorder is featured by a prolonged bleeding time, normal platelet count, and a decreased or absent ristocetine-induced platelet aggregation in combination with a prolonged aPTT and normal PT due to low levels of factor VIII/von Willebrand factor (vWF) parameters in the absence of a factor VIII inhibitor in the Bethesda assay. In vitro and vivo experiments consistently showed that the anti-vWF autoantibodies in monoclonal gammapathies cause a rapid clearance of the factor VIII/vWF complex from the circulation after DDAVP and factor VIII/vWF concentrate infusion. Multimeric analysis of the vWF usually show a type II-like AvWD due to the absence of large vWF multimers as the consequence of the rapid clearance of the anti-vWF-factor VIII/vWF complex from the circulation. There is a poor response to intravenous DDAVP and factor VIII/vWF concentrate infusion, but high dose intravenous gamma globulin (1 g/kg for 2 days) usually induces a transient correction of the factor VIII/vWF parameters for 1 to a few weeks.