Aminotransferase levels do not always increase during acute hepatitis or during an acute flare-up of chronic hepatitis. Persistently increased levels of serum alpha-Fetoprotein in an adult with liver disease suggest not only the presence or progression of hepatocellular Carcinoma or its recurrence after hepatic resection or after other therapeutic approaches such as chemotherapy or chemoembolization, but also it suggests that there is an acute exacerbation of hepatitis or liver cirrhosis. We report here on two unusual cases of HBV- & HCV-related liver cirrhosis with acute exacerbation of hepatitis in which there was an insignificant elevation of the aminotransferase levels, but there were markedly increased alpha-Fetoprotein levels observed. The levels of alpha-Fetoprotein decreased gradually in both cases since the beginning of antiviral therapy, which implies that the increased levels were due to aggravation of the accompanying hepatitis. These cases also emphasize that using only the measurement of alpha-Fetoprotein is not sufficient for the diagnosis of hepatocellular carcinoma, and that this diagnosis also requires a more specific measurement such as AFP L3 along with the standard imaging studies.