We studied the prevalence of long-term responders to interferon-alpha (IFN-alpha) treatment (undetectable levels of serum IgM anti-HBc, HBV-DNA and normal ALT values for 3 years) in 53 anti-HBe-positive chronic hepatitis B patients. Forty-two of them were treated with (6-18 MU) alpha-2a-recombinant-IFN t.w. for 4-6 months, and the remaining 11 with 10 MU of lymphoblastoid-IFN thrice weekly for 6 months. At the end of treatment, HBV-DNA levels were undetectable and ALT values within the normal range in 34 of 53 patients (60%); IgM anti-HBc levels decreased in all the 34 patients, falling below 10 PEI U in 2/34 (6%). Response to treatment was maintained throughout the follow-up (mean 3 years, range 2-7 years) in five patients (9.4%). The remaining 29 patients experienced HBV reactivation within median follow-up of 6 months (range 1-22 months; 90% of cases within 12 months). Overall 4/9 long-term responders (44.4%) cleared serum HBsAg. In conclusion, chronic anti-HBe-positive hepatitis B has a lower IFN treatment response rate than the HBeAg-positive form; however, among long-term responders, the incidence of serum HBsAg clearance is comparable in the two forms. Because of the high rate of relapses, stringent monitoring criteria (HBV-DNA, IgM anti-HBc and ALT monthly tested for at least 12 months) are mandatory.