The randomised clinical trials testing the effectiveness of interferon treatment on Chronic Hepatitis B patients were reviewed by means of meta-analysis. Twenty-two trials, published between 1987 and 1990, have identified where 1290 adult patients had been studied. Overall, interferon increased the rates of serum HBV-DNA clearance and amino-transferases normalization about 3 times at one year. However, when an analysis of internal consistency, clinical relevance and methodology of these studies was made, the trials were not sufficient to confirm the clinical effectiveness of the treatment since they had been planned for short-term assessment based on biochemical and viral end points alone. The link of these end points to other outcomes of more obvious clinical relevance (i.e. evolution to cirrhosis or deterioration of cirrhosis, death) is, in fact, questionable and thus the value of a meta-analysis based on currently available trials is uncertain as a source for practical guidelines. We conclude that the effectiveness of interferon in patients with chronic hepatitis B has yet to be confirmed by long-term prospective studies which assess the outcome by clinically meaningful end points such as cirrhosis, liver failure, or death.