Aim of this study was to evaluate the prognostic value of sMAO activity, assayed by benzylamine colorimetric method. Has been studied the correlation between clinical signs of portal hypertension (splenomegaly, ascites and varices) and sMAO levels; there was a significant increase of enzyme activity in chronic active hepatitis (CAH) with splenomegaly vs. CAH without, and in liver cirrhosis (LC) with splenomegaly and/or varices vs. LC without; there was also a correlation between sMAO and gamma-globulins levels in CAH and not in LC patients. In conclusion has been discussed the prognostic value of sMAO activity in CAH.