Previous studies have pointed to the changes of serum angiotensin-converting enzyme (SACE) values in patients with liver disease and cancer located in different sites. The aim of this study was to determine the changes in SACE values in patients with hepatocellular carcinoma (HCC) and liver cirrhosis. The study comprised 30 patients with HCC (20 males and 10 females) of average age 59.27±8.45years and 30 patients with liver cirrhosis (19 males and 11 females) of average age 52.9±10.78 years. The control group consisted of 30 healthy volunteers. SACE activity was determined by a Spectrophotometric method. The mean SACE value was considerably lower in patients with HCC (28.35±6.38 U/ml) compared to liver cirrhosis and control groups. The mean value of SACE was significantly correlated to the degree of differentiation of the tumor.In patients with liver cirrhosis SACE value was statistically significantly increased compared to HCC and control group (69.6±7.84 U/ml).It was found that there was a negative correlation between alpha-fetoprotein (AFP) value and ACE value.The study has shown that SACE values are low in patients with advanced HCC. It may be helpful in detecting HCC in patients with cirrhosis, where it can be difficult to differentiate between small HCC and regeneration nodules.