Infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and syphilis are serious complications of blood transfusion. These infections are routinely screened by blood banks; such tests are obligatory for transfusion safety in Turkey. The results of screening 1 737 943 blood donations from blood centres in Istanbul between 1 January 1987 and 31 December 2003 for HBV, HCV, HIV and syphilis were analysed retrospectively. Hepatitis B surface antigen rates fell from 5.98% in 1987 to 2.07% in 2003. Anti-HCV seropositivity was found to be approximately 0.5%, whereas anti-HIV seropositivity was approximately 0.001%. Rapid plasma reagin rates (test for syphilis) were 0.04% in 1987, and increased to 0.2% in 2002. The decreasing trends observed in data from the 17-year period studied indicate the value of safety measures taken, in particular the implementation of donor screening procedures in 1997.