Objective: To assess the efficacy of a screening program of ultrasonography (U.S.) every six months in the early diagnosis of HCC in liver cirrhosis patients. Patients and methods: We review retrospectively the 99 HCC detected by U.S. in our service from January 1998 to July 1994, We compared patients in the ultrasonography screening program (Group I) with patients who did not (Group II) and, also with, patients with a previous diagnosis of cirrhosis (Group IIa) and patients with simultaneous HCC diagnosis of and cirrhosis (Group IIb), Liver function, the tumor size and extension, and the chance of treatment at the time of diagnosis were analyzed in each group. Results: Twenty (58%) HCC out of 34 from group I single nodules <5 cm in diameter vs seven (11%) out of 65 from group II (p<0.001) were detected and this difference persisted between group I and groups IIa and IIb (p=0.002 and p< 0.001). Most patients with grade C Child-Pugh's score (24 from 27) in each group showed a >5 cm or multinodular HCC. Ten patients from group I were treated vs 4 from group II (p=0.001). Conclusions: Ultrasonography screening program is useful in the early diagnosis of HCC in liver cirrhosis patients and increases the chances of treatment.