Hepatocellular carcinoma, is one of the most common malignanciesin the world, it is a multifocal and aggressive tumor and it is the fourthmost common tumor in the world today. It is now a rather commonmalignancy in Egypt. HCC is one of the major causes of death because itshigh frequency and poor prognosis, it is responsible for about one milliondeaths annually with only few patients surviving beyond one year. It isone of the few human cancers for which an etiological factor can beidentified in most cases.the two main etiological factors for hepatocellularcarcinoma are cirrhosis and viral hepatitis (HCV & HBV), also the risk ofHCC increased with prolonged dietary consumption of aflatoxins, alcoholor iron overload.In Egypt the incidence of HCC is increased due to the highprevalence rate of HCV which accounts for most of cirrhosis and HCCcases.Early detection of patients with HCC is attractive because it givesbetter prognosis, and earrly detection is not difficult if tumor markers andmedical imaging were possible, so the need for easy reliable tumormarker is mandatory because AFP may be within normal in HCC cases,and if elevated it nees high cutoff values to be sure of the diagnosis alsoimaging is important to be combined with the tumor markers to be sure ofthe diagnosis, so 3D US used with 2D US to be more accurate, and it canmeasure the actual volume of the tumor and any loal spread.The aim of this study was to determine the value of alpha-Lfucosidaseactivity enzyme as a possible tumor marker of HCC patientswith low AFP. The study was conducted on 30 HCC cases, 21 of 30 with low AFP (< 400 ng/ml) and 9 with high AFP (> 400 ng/ml) and 20normal subjects. We determined the levels of AFP and AFU for all casestogether with liver bichemical profile, abdominal US and histopathologicexamination of the hepatic focal lesion in HCC cases. We concluded thatthe diagnostic sensitivity of AFU at a cutoff U/L was % and thespecificity %. The median level of AFU was above its cutoff value forHCC patients with low levels of AFP. In our study no significantcorrelation was found between AFU and low AFP levels.