In severe von Willebrand’s disease (vWD), the multimeric analysis of von Willebrand factor (vWF) has been hindered by the low content of the protein although different patterns have been observed by radiocrossed immunoelectrophoresis (RCIE). Cryoprecipitate and vWF concentrate were obtained from the plasma of a severe vWD patient, that on RCIE had only the more anodic forms. The sodium dodecylsulfate (SDS) agarose analysis evidences the presence of the main bands, a relative increase of the smaller forms and a lesser definition of some minor bands. These findings suggest the possibility of structural abnormalities in severe vWD. The study of cryoprecipitates could be a means to evidence the presence of multimers and the extent of the eventual pattern variabilit