Human immunodeficiency virus (HIV) infection and hepatitis virus B or C (HBV, HCV) transmission are major risks following infusion of coagulation factor concentrates. Thus, several methods have been used to achieve viral inactivation of concentrates prepared from plasma collected from a large number of donors. In this study, 32 patients with haemophilia A or B (n = 31) or von Willebrand's disease (n = 1) were treated between 1987 and 1990 only with factor VIII or IX concentrates inactivated by the solvent-detergent procedure. During this period, none of these cases exhibited elevated liver enzymes (alanine amino transferase), and serological tests for HIV, HBV and HCV infections always remained negative. This suggests that the solvent-detergent procedure of concentrate inactivation is an efficient method to prevent not only HIV or HBV transmission but also HCV infection in haemophiliacs.