The size and the treatment of 135 hepatocellular carcinomas (HCC) has been analyzed, comparing patients diagnosed by a US screening program (group 1) and these diagnosed outside this program (group 2) to determine whether US screening on patients with chronic liver disease is able to diagnose (HCC) at an early stage. alpha-fetoprotein levels above 500 U/ml were considered as diagnostic. Twenty (46.5%) out of 43 patients from group 1 showed a HCC < 5 cm. vs. 14/92 (15.2%) in group 2 (p = 0.001). Only 5.9% of the HCC < 5 cm. showed AFP > 500 U/ml. vs. 29.7% of the advanced HCC (p = 0.003). 88.3% of patients of group 1 vs. 63% of group 2 received specific treatment for HCC (p = 0.002). By means of US screening it is possible to diagnose HCC of smaller size and more susceptible to treatment. AFP is not useful in the early diagnosis of HCC.