11,117 blood donors from 24 blood transfusion services evenly distributed throughout the various Italian regions were tested for the presence of hepatitis C virus (HCV) antibodies in the serum and serum alanine aminotransferase (ALT) level. The results are as follows: (1) anti-HCV seroprevalence in Italy was 0.87% with a difference between Northern and Southern regions (0.68 vs. 1.37%) and between younger and older subjects (0.62 vs. 1.21%); (2) prevalence of elevated ALT levels was 4.74% without a North-South effect (except than for markedly elevated ALT levels); (3) anti-HCV seroprevalence was higher in subjects with elevated ALT (5.0%), with a North-South effect (2.2 vs. 9.9%) and particularly high (19.2%) in subjects with markedly elevated ALT; (4) ALT levels were elevated in 26.2% of anti-HCV positive subjects, with a North-South effect (14 vs. 40.5%).