A total of 4683 donated blood units were screened for HCV-Ab, HBs-Ag, HIV-Ab, VDRL, malaria parasites and ALT between January 1993 and April 1994. Of the blood units, 7.7% were positive for one or two hepatitis markers (HCV-Ab, HBs-Ag), while 4.6% were positive for HCV antibody, and 3.3% of the 4.6% were accounted for by Egyptian blood donors. Thus, 73% of all positive blood units for HCV-Ab were from Egyptian donors, while the rate of positive blood units for Saudi blood donors was 0.9%. Three and one-tenth percent of the total blood units were positive for HBs antigen, 2.3% from the Saudi population. Thus, 75% of all positive blood units were from Saudi donors. The percentage for HBs-Ag blood units for Egyptians was 0.3%. The exact prevalence of HCV-Abpositive blood units among Saudis was 1.2% and HBs-Ag-positive units was 3.3%. Prevalence of HCV-Ab-reactive blood units among Egyptians was 34% and HBs-Ag-positive units was 3.3%. HCV-RNA using PCR was detected in a total of 86% of the individuals reactive to HCV antibody. Forty-three percent of hepatitis-B-and/or C-reactive blood donors had elevated alanine aminotransferase (ALT). Elevated ALT was observed in a higher percentage among HCV-Ab-reactive blood donors as compared to HBs-Ag-reactive donors. Blood donors are a major source of diseases, especially viral infection. The most common blood-transmitted viruses are HBV, HCV and HIV. These viruses cause fatal disease and chronic and life-threatening disorders. Local, not imported, donated blood units at King Fahad Hospital, Al Baha, are screened for HCV-Ab, HBs-Ag, HIVantibody, VDRL, malaria parasites and liver function (alanine aminotransferase, or ALT). If blood units were reactive to any one parameter, they were rejected and the donor was advised to visit the internal medicine clinic. IgG antibody to HCV was detected in 93% of acute and 91% of chronic non-A non-B hepatitis cases.1 This finding points to the possibility of transmission of HCV even when blood units are nonreactive to HCV-Ab. The introduction of the ALT value as a parameter will help to reduce the risk of transmitting HCV through transfusion. ALT value greater than the upper limit (65 U/L) by factor 1.5 (97 U/L) was taken as the criterion for rejecting the blood unit. Repeated ALT value greater than 97 U/L by a second blood donation from the same donor was considered as permanent rejection for any blood donation in the future. Excluding the use of donated blood with abnormal ALT results may have reduced the incidence of post-transfusion hepatitis. 2The prevalence of HBV or HCV varies by nationality and geography. The prevalence of HBV infection among Saudi donors is known to be about three times higher than the incidence of HCV infection 3,4 and the prevalence of HCV infection among Egyptian donors is high as well. 5,6 The prevalence of HCV antibody among Saudi blood donors at four hospitals in the Riyadh area ranges between 1.0 to 1.7%, averaging 1.3%. 3,4,7,8 Material and MethodFour thousand, six hundred and eighty-three donated blood unit...