Hepatitis B surface antigen was determined by radioimmunoassay in 2487 male Saudi and 7587 Western expatriate volunteer blood donors. The HBsAg positivity rate was 8.5% in males Saudis and 0.7% in Western expatriate blood donors. This study was further extended to test other hepatitis B virus (HBV) markers and alanine aminotransferase (ALT) in 200 consecutive Saudi male blood donors' sera. A positivity rate for HBsAg was 8.5%, anti-Hbs was 35.5%, anti-HBc (alone) was 1.5%, HBeAg was 1.0%, and anti-HBe was 2.5%. A suggested nonspecific screening test for ALT enzymes with levels of ≥ 45 IU/L (normal 6-36 IU/L) for non-A, non-B hepatitis carrier state was performed on the 200 male Saudi blood donor sera, using Dupont ACA III methodology. The result showed an elevation of enzyme in 2.5% of Saudi donors. If a blood donor with any HBV marker were excluded the only 1.5% showed ALT enzyme elevation, considerably lower than the reported 3.6% in the U.S. blood donor population. The positivity rates of 8.5% for HBsAg, 35.5% for anti-HBs and 49% for any HBV serological markers in male Saudi blood donors are significantly higher than in American volunteer blood donors.