There remains a small risk of viral transmission from single-donor blood components such as fresh frozen plasma (FFP) and cryoprecipitate which have not been subjected to a viral inactivation procedure. It is now possible to subject pooled FFP to viral inactivation by the solvent detergent (SD) treatment method, but with some loss of coagulation factors. To establish whether cryoprecipitate prepared from SD plasma would be suitable for the treatment of hypofibrinogenaemia and von Willebrand's disease (VWD), control and SD cryoprecipitate were assayed for factor VIII. von Willebrand factor (VWF) and fibrinogen content. In SD cryoprecipitate, levels of VWF activity and antigen were only 36% and 37% of control values respectively, whereas fibrinogen was 72%. The highest molecular weight multimer of VWF:Ag were absent from both SD plasma and SD cryoprecipitate. SD cryoprecipitate would thus be unsuitable for treating VWD, but would provide an alternative to untreated individual donor units of cryoprecipitate for the treatment of hypofibrinogenaemic states.